*.i:< , .(U\;i;i;^;;>;..;/; l ' (l ;: < ,;,v. u y 4 ;,»;';-:; 
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Class, WV\ 
Book _ 
GopyrightN°_ 

COPYRIGHT DEPOSIT. 



PRINCIPLES AND PRACTICE 



OF 



Operative Dentistry 



BY 
JOHN SAYRE MARSHALL, M.D. (Syr. Univ. 

DENTAL SURGEON UNITED STATES ARMY 
PRESIDENT ARMY EXAMINING BOARD FOR DENTAL SURGEONS 




PHILADELPHIA AND LONDON 

J. B. LIPPINCOTT COMPANY 
1901 



1 






(TO 



I 



av 



THE LIBRARY OF 
CONGRESS, 

Two Cowea Received 

OCT. 8 1901 

Copyright entry 

CLASS O-XXc No. 

9997 
COPY J. 



Copyright, 1 901 

BY 

J. B. Lippincott Company 



' LEC 1 UNTYPED AND PRINTED 



LIPPINCOTT COMPAN 



PHILADELPHIA, 



Zo tbe flUemon? of m^ more tban tfrienD 

THE LATE 

DR. JAMES W. WHITE 

EDITOK OF THE DENTAL COSMOS 

WHO THROUGH THE NOBLENESS OF HIS CHARACTER BECAME 

THE INSPIRATION OF EVERY YOUNG MAN WHO CAME 

WITHIN THE SPHERE OF HIS INFLUENCE 

THIS VOLUME 

IS AFFECTIONATELY DEDICATED BY 

THE AUTHOR 



PREFACE. 



In the preparation of this volume the author has kept in mind the needs 
both of students and of practitioners of dental surgery. 

It has been his endeavor so to present the subject-matter as to give the 
student a comprehensive view of the principles and practice of operative 
dentistry, arranged in a natural and orderly sequence. This plan has also 
been carried out in the presentation of each individual topic, in the hope 
that the student will thereby be helped in his understanding of the various 
phases of each department of the subject and likewise taught to be me- 
thodical in his studies and operations. It is also hoped that the dental 
practitioner will find in the work material which will assist him in his 
investigations of those pathologic conditions of the teeth and their con- 
tiguous parts, and the surgical methods employed in their treatment, that 
occupy so large a part of his time, energy, and skill. 

The methods of constructing artificial crowns and bridge- work have 
not been included in this volume, because in the opinion of the author 
they properly belong to the department of prosthetic dentistry. The 
subject of orthodontia has also been excluded, for the reason that this 
branch has assumed the proportions of a separate specialty, and would 
therefore occupy more space than could be given to it in a work of this 
size and character. 

The author desires to acknowledge his great indebtedness to his friend 
Dr. Vida A. Latham, of Chicago, for her valuable services in the prepara- 
tion of numerous original and interesting photomicrographs of normal and 
pathologic dental tissues and of bacteriologic specimens ; also to his friends 
Dr. E. E. Andrews, of Cambridge, Massachusetts, and Mr. James S. 
Shearer, of Bay City, Michigan, for the use of a number of original photo- 
micrographs from their valuable collections ; to Dr. W. D. Miller, of 
Berlin, Germany ; to Dr. J. Leon Williams, of London, England ; to Dr. 
Filandro Vincentini, of Naples, Italy ; to Dr. Matt H. Cryer, of Philadel- 
phia, and to Dr. Frederick B. Noyes, of Chicago, for the privilege of 
reproducing and using several illustrations from the published accounts 
of their investigation^. 

The author also acknowledges the courtesy extended by Dr. Wilbur F. 
Litch, Dr. G. V. Black, and the publishers of the "American System of 



VI PREFACE. 

Dentistry ;" by Dr. Edward C. Kirk and the publishers of the u American 
Text- Book of Operative Dentistry ;" by the late Dr. Henry H. Burchard 
and the publishers of his "Dental Pathology, Therapeutics, and Pharma- 
cology ;" by Mr. Charles Tomes, F.B.C.S. , of London, England; by the 
S. S. White Dental Manufacturing Company, and by others, for the privi- 
lege of reproducing many valuable illustrations. 

Acknowledgment is also due to his friend Dr. Bertha E. Bush, of 
Chicago, for much valuable and time-saving assistance in reading and 
correcting the proofs. 

Chicago, August 1* 1901. 



CONTENTS. 



CHAPTER I. 

PAGE 

Classification and Descriptive Anatomy of the Teeth 1 

Number and Classification of the Teeth — Descriptive Anatomy of the 
Teeth — Architectural Design of the Teeth — The Incisors — The Cuspids 
—The Bicuspids— The Molars— The Deciduous Teeth. 



CHAPTER II. 

Origin, Development, and Morphology of the Teeth 26 

Evolution of Epithelial Tissue — Evolution of the Jaws — Evolution of 
the Teeth. 

CHAPTER III. 

Histology of the Dental Tissues 34 

Enamel — Striae — Chemic Composition of Enamel — Calcification of 
Enamel — Stratum Intermedium — Blood-Supply of the Enamel-Organ 
— Dentin — Matrix — Dentinal Tubuli, Sheaths, and Fibrils — Interglobu- 
lar Spaces — Development of the Root — Dentinification — Cementum — 
Cementification — Chemical Composition of Calcified Tissues — Nas- 
myth's Membrane — The Teeth-Pulp — The Peridental Membrane- 
The Gums. 

CHAPTER IV. 
Eruption of the Teeth 59 



Deciduous Teeth — The Eruptive Process — Growth of the Jaw — Morbid 
Primary Dentition — Exuviation or Shedding of the Deciduous Teeth — 
Eruption of the Permanent Teeth. 



CHAPTER V. 
Bacteriology of the Mouth 



Parasites — Classifications — Mouth Bacteria Proper — Bacteria which 
affect the Integrity of the Dental Tissues— Sterilization of Hands and 
Instruments — Technique of Sterilization. 



CHAPTER VI. 

Examination of the Teeth and Mouth 107 

Position of Patient and Operator — Instruments used in Examinations — 
The Examination. 

vii 



Vlll CONTENTS. 



CHAPTER VII. 

PAGE 

Dental Caries 115 

Distribution — Results of the Examination of Ancient Crania— Preva- 
lence of Dental Caries— Etiology — Constitutional Predisposing Causes — 
Local Predisposing Causes. 

CHAPTER VIII. 

Dental Caries (Continued) 135 

Theories of Caries — Caries of Enamel — Caries of Dentin — Penetration 
of Caries — Caries of Cementum. 



CHAPTER IX. 
Dental Caries (Continued) 161 

Varieties — Stages — Symptoms — Diagnosis — Prognosis. 

CHAPTER X. 

Treatment op Caries. Prophylaxis 166 

Cleanliness of the Mouth and Teeth — Dentifrices— Antiseptics. 

CHAPTER XL 

Treatment of Caries (Continued) 171 

Medication— Excision. 

CHAPTER XII. 

Treatment of Caries ( Continued) 174 

Methods of Separation of Contiguous Teeth — Exclusion of Moisture. 

CHAPTER XIII. 
Hypersensitive Dentin 184 

Causes of Hypersensitive Dentin — Treatment— Palliative Treatment — 
Chemical Treatment — Heated Air, etc. 

CHAPTER XIV. 
Cataphoresis 193 

Osmosis — Anodal Electrolysis — Cathodal Electrolysis — The General 
Principles or Laws which govern the Generation and Transmission 
of Electricity — Rheostats ; Current Selectors ; Current Controllers — 
Electrococaine Ansesthesia — Method of Administration — General 
Ansesthesia. 

CHAPTER XV. 
The Classification of Cavities 217 

Simple Cavities upon Exposed Surfaces— Simple Approximal Cavities 
— Compound Cavities. 



CONTENTS. 



CHAPTER XVI. 

PAGE 

Preparation of Cavities 234 

Opening the Cavity — Removing Decay — Retentive Shaping — Forming 
Cavity Margins. 

CHAPTER XVII. 

Treatment op Caries by Obturation, or Filling 250 

Filling-Materials and their Introduction — Non-Plastic Materials — 
Physical Characteristics of Gold — Properties of Gold-Foil — Non- 
Cohesive Foil — Cohesive Foil — Plugging Instruments — Crystal or 
Sponge Gold — Gold-and-Platinum Foil — Annealing. 



CHAPTER XVIII. 

Considerations in Filling Special Classes op Cavities 272 

Simple Cavities upon Exposed Surfaces — Simple Approximal Cavi- 
ties — Compound Cavities — Matrices — Tin-Foil — Tin and Gold — Finish- 
ing Fillings — Repairing Defective Gold Fillings. 



CHAPTER XIX. 

Plastic Filling-Materials. Amalgam 296 

The Nature and Properties of Amalgam — Chemic Relations — Com- 
position of Alloys— Making Dental Alloys. 



CHAPTER XX. 

Manipulation and Introduction op Plastic Filling-Materials 321 

Especial Uses of Amalgam — Mixing Amalgams — Introduction of Amal- 
gams—Copper Amalgam — Gutta-Percha — Zinc Cements — Varnishes. 



CHAPTER XXI. 
Inlays 346 

Metal— Porcelain— Glass— Methods of Manipulation. 



CHAPTER XXII. 

Denudation or Erosion of the Teeth, and Attrition or Abrasion 359 

Causes — Pathology — Treatment. 

CHAPTER XXIII. 

Diseases and Injuries of the Dental Pulp and Their Treatment 373 

Hyperemia of the Dental Pulp— New Formations — Calcifications. 



CONTENTS. 



CHAPTER XXIV. 

PAGE 

Inflammation op the Dental Pulp 397 

Table of Inflammatory Phenomena— Inflammation of the Pulp— Sup- 
puration of the Dental Pulp— Chronic Inflammation of the Dental 
Pulp. 

CHAPTER XXV. 

Exposure of the Dental Pulp and its Treatment 416 

Secondary Dentin, or Dentin of Repair — Devitalization and Extirpa- 
tion of the Pulp — Physical Effects of Arsenic upon the Pulp. 



CHAPTER XXVI. 

Pulpless Teeth and Filling Pulp-Canals 431 

Preparation and Treatment of Pulp-Canals — Materials Employed for 
Filling Pulp-Canals and Methods of Introduction— Mummification of 
the Pulp. 

CHAPTER XXVII. 

Bleaching Discolored Teeth 446 

Preparation of the Tooth for Bleaching— Method of Bleaching — Chlo- 
rine Methods— Truman Method— Dioxide Methods — Sulphurous An- 
hydride Method — Cataphoric Method. 



CHAPTER XXVIII. 

of the Pericementum 459 

Pericementitis— Subacute and Chronic Pericementitis— General Non- 
Septic Pericementitis — Tubercular Pericementitis— Scorbutic Perice- 
mentitis— Mercurial Pericementitis. 



CHAPTER XXIX. 
Dento- Alveolar Abscess 474 

Causes — Varieties— Pathology — Formation of Pus— Location — Chronic 
Dento- Alveolar Abscess — Treatment. 



CHAPTER XXX. 

Replantation of the Teeth 490 

Indications calling for Replantation — Persistent Alveolar Abscess. 

CHAPTER XXXI. 

Transplantation and Implantation of the Teeth 494 

Transplantation of Teeth — Implantation of Teeth — Requirements for 
the Operation — Method of Operation. 



CONTENTS. XI 



CHAPTER XXXII. 

PAGE 

Dislocation of the Teeth 501 

Partial and Complete Dislocations — Treatment — Prognosis. 



CHAPTER XXXIII. 
Fkactukes of the Teeth 505 

Simple, Compound, and Comminuted Fractures— Treatment — Union 
of Fractured Teeth. 

CHAPTER XXXIV. 

Resorption of the Roots of Permanent Teeth 509 

Causes — Pathology — Symptoms and Diagnosis— Prognosis — Treatment. 

CHAPTER XXXV. 

Hypercementosis 513 

Causes — Pathology — Inostosis — Symptoms and Diagnosis — Treatment. 

CHAPTER XXXVI. 

Necrosis of the Teeth 518 

Causes— Partial Necrosis — Treatment. 



CHAPTER XXXVII. 

Deposits upon the Teeth. Green Stains. Calcic Deposits 521 

Composition of the Saliva— Salivary Calculus — Varieties — Treatment — 
Scalers. 

CHAPTER XXXVIII. 
Pyorrhea Alveolaris 530 

Constitutional Origin of the Disease— Local Origin of the Disease- 
Bacterial Origin of the Disease — Ptyalogenic Calcic Pericementitis : 
Causes — Pathology and Morbid Anatomy — Symptoms and Diagnosis — 
Prognosis — Treatment. 



CHAPTER XXXIX. 

HEMATOGENIC CALCIC PERICEMENTITIS 550 

Causes— Varieties — Pathology and Morbid Anatomy — Symptoms and 
Diagnosis — Prognosis — Treatment. 



CHAPTFR XL. 

Phagedenic Pericementitis 568 

Causes — Pathology — Symptoms and Diagnosis — Prognosis — Treatment. 



CONTENTS. 



CHAPTER XLI. 

PAGE 



Anaesthetics, Local and General 578 

Local Anaesthetics — Anaesthesia by the Local Abstraction of Heat- 
Richardson's Method — Letamendi's Method— Anaesthesia by the Local 
Narcotic Effect of Drugs — Cocaine — Eucaine — Chloretone — General 
Anaesthetics — Nitrous Oxide — Hewitt's Method — Examination of the 
Physical Condition of the Patient — Precautions against Accidents— 
Administration of Ether. 



CHAPTER XLII. 
Extraction of Teeth 

Indications which call for the Extraction of Teeth — General Condi- 
tions Unfavorable to Extraction — Instruments used in the Operation 
of Extracting — Selection of the Proper Instruments for the Extraction 
of the Various Classes of Teeth, their Proper Adjustment, and the 
Kind and Direction of the Force applied — Extraction of the Roots of 
Teeth — Difficulties, Complications, and Accidents. 



LIST OF ILLUSTRATIONS. 



PLATES. 

PLATE PAGE 

I. Varicosed enamel-rods, magnified 36 

II. Varicosed enamel-rods, very highly magnified 37 

III. Normal dentin showing tubuli in cross-section, highly magnified 44 

IV. Normal dentin showing tubuli in longitudinal section, highly magnified 45 

V. Leptothrix racemosa, early stages 96 ' 

VI. Leptothrix racemosa, later stages 97 

VII. Abnormal root-canals 435 

FIGURES. 

FIG. 

1. A T ertical section of inferior maxilla and teeth of mole, X 15 2 

2. Deciduous teeth of the left side 2 

3. Permanent teeth of the right side ■ 2 

4. Structures of a tooth 2 

5. Occlusion of the teeth 3 

6. Superior left central incisor, labial surface 3 

7. Superior right central incisor, labial surface 3 

8. Superior left central incisor, labial surface 6 

9. Superior left central incisor, lingual surface 6 

10. Superior left central incisor, mesial surface 6 

11. Superior left central incisor, distal surface 6 

12. Superior right lateral incisor, labial surface 7 

13. Superior right lateral incisor, lingual surface 7 

14. Superior lateral incisor with exaggerated cervical ridge 7 

15. Superior right lateral incisor, mesial surface 7 

16. Superior right lateral incisor, distal surface 7 

17. Inferior right central incisor, labial surface 8 

18. Inferior right central incisor, lingual surface 8 

19. Inferior right central incisor, mesial surface 8 

20. Inferior right central incisor, distal surface 8 

21. Inferior right lateral incisor, labial surface 9 

22. Inferior right lateral incisor, lingual surface 9 

23. Inferior right lateral incisor, mesial surface 9 

24. Inferior right lateral incisor, distal surface 9 

25. Superior right cuspid, labial surface 10 

26. Superior right cuspid, lingual surface 10 

27. Superior right cuspid, mesial surface 10 

28. Superior right cuspid, distal surface 10 

29. Inferior right cuspid, labial surface 11 

30. Inferior right cuspid, lingual surface 11 

31. Inferior right cuspid, mesial surface 11 

32. Inferior right cuspid, distal surface 12 

33. Superior right first bicuspid, buccal surface 12 

34. Superior right first bicuspid, lingual surface 12 

35. Superior right first bicuspid, mesial surface 12 

36. Superior right first bicuspid, distal surface 12 

xiii 



XIV LIST OF ILLUSTRATIONS. 

FIG. p AGE 

37. Superior right first bicuspid, morsal surface " 13 

38. Superior right second bicuspid, buccal surface 13 

39. Superior right second bicuspid, lingual surface 13 

40. Superior right second bicuspid, mesial surface 13 

41. Superior right second bicuspid, distal surface 14 

42. Superior right second bicuspid, morsal surface 14 

43. Inferior right first bicuspid, buccal surface 14 

44. Inferior right first bicuspid, lingual surface 14 

45. Inferior right first bicuspid, mesial surface 15 

46. Inferior right first bicuspid, distal surface 15 

47. Inferior right first bicuspid, morsal surface 15 

48. Inferior right second bicuspid, morsal surface 15 

49. Inferior right second bicuspid, buccal surface 16 

50. Inferior right second bicuspid, lingual surface 16 

51. Inferior right second bicuspid, mesial surface 16 

52. Inferior right second bicuspid, distal surface 16 

53. Superior right first molar, buccal surface 17 

54. Superior right first molar, lingual surface 17 

55. Superior right first molar, mesial surface 17 

56. Superior right first molar, distal surface 17 

57. Superior right first molar, morsal surface 18 

58. Superior right second molar, buccal surface 18 

59. Superior right second molar, lingual surface 18 

60. Superior right second molar, mesial surface 18 

61. Superior right second molar, distal surface 19 

62. Superior right second molar, morsal surface 19 

63. Superior right third molar, buccal surface 19 

64. Superior right third molar, lingual surface 19 

65. Superior right third molar, mesial surface 20 

66. Superior right third molar, distal surface 20 

67. Superior right third molar, morsal surface 20 

68. Inferior right first molar, buccal surface 20 

69. Inferior right first molar, lingual surface 21 

70. Inferior right first molar, mesial surface 21 

71. Inferior right first molar, distal surface 21 

72. Inferior right first molar, morsal surface 21 

73. Inferior right second molar, buccal surface 22 

74. Inferior right second molar, lingual surface 22 

75. Inferior right second molar, mesial surface 22 

76. Inferior right second molar, distal surface 22 

77. Inferior right second molar, morsal surface 23 

78. Inferior right third molar, buccal surface 23 

79. Inferior right third molar, lingual surface 23 

80. Inferior right third molar, mesial surface _ 23 

81. Inferior right third molar, distal surface 24 

82. Inferior right third molar, morsal surface 24 

83. Deciduous teeth of the left side 25 

84. Graafian follicles, or ova, in various stages of development, X 80 26 

85. Division of mammal ovum 27 

86. 87, 88. Transverse section of embryo of chick 26 

89, 90. Vertical sections of human skin 27 

91. Squamous epithelium from buccal cavity, X 162 27 

92. Longitudinal section of lip of a kitten 27 

93. Transverse section of hairs of scalp, X 50 28 

94. Epithelial layer of the mucous membrane 28 

95. 96. Columnar epithelial cells, X 670 28 



LIST OF ILLUSTRATIONS. XV 

FIG. PAGE 

97. Goblet-cells, X 500 28 

98. Section of jaw of rabbit embryo 2S 

99. First rudiments of a hair from human embryo 28 

100. Lower jaw of human embryo, X 80 29 

101. Vertical section of skin, showing bulbous ends of hairs, X 55 29 

102. Head of human embryo 29 

103. Vertical section through head of human foetus, X 80 29 

104. Lower jaw of human foetus, X 80 29 

105. Involution of the Malpighian stratum 30 

106. Lower jaw of human embryo, X 75 30 

107. Vertical section of epithelial cord, or primitive enamel-organ, X 300 30 

108. Cross-section of epithelial cord, X 300 30 

109. Primitive epithelial cord, X 45 30 

110. Section through lower jaw of embryo mouse 31 

111. Evolution of dental follicle (ninth week), X 70 31 

112. Developing human cuspid 31 

113. Follicle of human molar (eleventh week), X 50 31 

114. Human embryo (twelfth week) 32 

115. Vertical section of human molar at junction of enamel-organ with dentin 

papilla?, X 300 32 

116. Vertical section of incisor of human foetus 32 

117. Oblique section of a dental follicle 32 

118. Vertical section of human molar, early stage of calcification, X 90 32 

119. Vertical section of cuspid of human foetus, budding of primitive epithelial 

cord, X 70 32 

120. Vertical section of human foetal maxilla, X 70 33 

121. Vertical section of human foetal incisor, X 50 33 

122. Section of human developing tooth 33 

123. Section of dental follicle of cat, X 9 33 

124. Vertical section of cuspid, human foetus, X 50 33 

125. Vertical section of molar, human foetus, X 70 33 

126. Section of dental follicle, first layers of ameloblasts and odontoblasts, X 100.. 34 

127. Section of f cetal femur, showing odontoblasts, X 109 31 

128. Forming dentin, showing odontoblasts, X 1900 35 

129. Enamel-cells, with nuclei 35 

130. Dentinal sheaths 36 

131. 132. Enamel-columns, highly magnified 36 

133. Developing molar, ends of enamel-rods, X 1000 36 

134, 135. Sections of enamel-rods, odontoblasts, and dentin 37 

136. Section of enamel, striations of Retzius, X 1 10 38 

137. Section of dental follicle, first layer of ameloblasts, X 325 3S 

138. Teased section of developing molar, showing ameloblasts, X 1000 38 

139. Developing enamel, Tomes's processes 38 

140. Section of developing human molar, X 1000 39 

141. 142. Section of developing tooth, ameloblasts highly magnified 39 

143. Transverse section of developing tooth, X 275 39 

144. Developing tooth of embryo lamb, X 105 40 

145. Section of human foetal incisor ; blood-supply of enamel-organ 40 

146. Section of dental follicle of rat, papillary layer, X 90 40 

147. Section of forming enamel (rat), X 325 40 

148. Section of incisor of rat, X 80 41 

149. Ground section of developing tooth of rat, X 97 41 

150. 151, 152. Forming enamel, calcoglobulin, formation of enamel-rods 41, 42 

153. Longitudinal section of incisor 42 

154. Longitudinal section of inferior molar 42 

155. Section of root of bicuspid, radiation of dentinal tubuli 43 



XVI LIST OF ILLUSTRATIONS. 

FIG. PAGE 

156. Dentinal tubuli at dento-enaruel junction, X 760 43 

157, 158. Sections of root, parallel to dentinal canals 43 

159. Section of dentin and enamel, tubuli entering the enamel 44 

160. Section of developing tooth, dentinal fibres passing from dentin to enamel, 

X 1000 44 

161. Dentinal sheaths, X 273 45 

162. Section of enamel and dentin, interglobular spaces, X 50 45 

163. Section of enamel and dentin, interglobular spaces, X HO 48 

164. Section of dentin and cementum, X 97 48 

165. Section of enamel and dentin, incremental lines, X 500 48 

166. Vertical section of foetal face, X 7 ! 48 

167. Section of human lower jaw, X 9 49 

168. Section of developing human cuspid, X 100 49 

169. Teased section of developing molar, X 1000 49 

170. Truncated odontoblasts and fibril cells 49 

171. Section of tooth-follicle, nuclei of odontoblasts, etc., X 325 50 

172. Odontoblasts 50 

173. 174. Sections of bone, X 60 51 

175, 176. Sections of cuspidati, magnified 52 

177, 178. Sections of molars, magnified 52 

179. Section of root of tooth and alveolus, X 80 53 

180. Section of alveolar process and cuspid, X 100 53 

181. Developing bone from scapula, X 50 53 

182. Section of enamel and Nasmyth's membrane, X 250 54 

183. 184. Sections of normal pulp-tissue, X 143 54 

185, 186, 187. Sections showing blood-supply of the pulp 55 

188. Injected dental pulp, X 8 56 

189. Nerves of dental pulp 56 

190. Pericementum and alveolar process between teeth, X 100 56 

191. Section through pulp-chamber of cuspid 56 

192. Periosteum surrounding ulnar and radius, X 13 56 

193. 194. Peridental membrane of forming tooth 56 

195. Section through alveolar process, X 30 57 

196. Section of root of tooth in situ 57 

197. Blood-vessels and nerves entering at base of dental follicle, X 96 57 

198. Section of pericementum in situ, X 408 57 

199. 200. Sections of peridental membrane, highly magnified 58 

201. Section of jaw through alveolar process, X 60 59 

202. Section of dental follicle and mucous membrane, X 26 59 

203. Glands of Serres, X 50 59 

204. Epithelial layer of embryonic mucous membrane 59 

205. Section of jaw, showing forming root, X 15 ■ . 60 

206. Follicles of permanent teeth at period of eruption of primary teeth, X 22.. . . 60 

207. Lower jaw of foetal mouse, X 80 61 

208. 209. Section of erupting tooth of mouse, area of resorption at cusp, magni- 

fied 61, 62 

210. Vertical section of human cuspid, X 75 62 

211. Rami at various ages 63 

212. Jaws of a young child 64 

213. 214. Sections of jaw of embryo cat, showing deciduous tooth and follicle of 

permanent tooth 64 

215. First and second dentition 66 

216-220. Eruption of teeth 71 

221. Gum-lancet 72 

222. Curved scissors 73 

223. Peculiar exuviation of a kitten's tooth, X 35 76 



LIST OF ILLUSTRATIONS. XVII 

FIG. PAGE 

224. Absorbent organ and portion of dentin, X 65 76 

225. Calcification and decalcification of teeth 78 

226. Fruit mould, X 130 84 

227. Forms of bacteria 85 

228. Various forms of yeast fungi 86 

229. Torula, or yeast fungi 84 

230. Bacterium typhosus, X 1000 88 

231. Bacillus pestis and blood-cells of rat, X 1000 88 

232. Pneumococcus, capsule form, X 1200 88 

233. Diplococcus pneumoniae, X 1000 88 

234. Streptococcus pyogenes, X 1000 80 

235. Streptococcus in pyaemia after erysipelas, X 660 89 

236. Bacteria in pus, X 700 80 

237. Bacillus tuberculosis, X 1000 89 

238. Flagellated spirillar and vibrio, X 2100 90 

239. Bacillus of hog cholera, X 1000 90 

240. Staphylococcus pyogenes, X 1000 91 

241. Streptococcus pyogenes, X 1000 91 

242. Streptococcus hominis, X 218.75 91 

243. Leptothrix buccalis, X 193.75 92 

244. Mouth bacteria (diplococci, leptothrix) 92 

245. Bacillus buccalis maximus, 1800 : 1 93 

246. Spirochaeta dentium (denticola) and leptothrix threads, X 1000 94 

247. Spirochasta dentium, showing flagella, X 1000 94 

248. Leptothrix gigantea, from dog, X 750 94 

249. 250. Leptothrix gigantea, X 1000 95 

251. Micro-organisms from enamel surface 100 

252-258. Leptothrix racemosa, fructification heads, etc 100 

259. Instrument-sterilizer 105 

260, 261. Dental mirrors 105, 109 

262-264. Magnifying-glasses 110 

265. Explorers Ill 

266. Electric mouth-lamp Ill 

267. Parr's universal separator 112' 

268. Perry's two-bar separators 113 

269. Syphilitic teeth 120 

270. 271. Caries following crack in enamel, X 95 132 

272, 273. Caries of enamel and dentin 156 

274. Undermining caries of enamel 157 

275. Section of a molar crown with caries 157 

276-293. Infected dentin and dentinal tubules 157-161 

294. Section of a molar showing stages of caries 162 

295. Corundum disks 173 

296. 297. Tooth-separators 176 

298, 299. Napkin clamps 178 

300. Rubber dam applied 180 

301. Rubber-dam holder 180 

302. Ivory clamps 181 

303. Ottolengui's clamp applied 181 

304. How's cervix screw-clamp 181 

305. Elliot's clamp and forceps 182 

306. Rubber-dam applier 182 

307. Ainsworth's rubber-dam punch 182 

308. Sizes of holes in rubber darn 183 

309. Depressed rubber dam 183 

310. 311. Denham coffer-dam shield 183 



XV111 LIST OF ILLUSTRATIONS. 

FIG. PAGE 

312. Mirror 183 

313, 314. Hot-air syringes 189 

315. Improved electric hot-air syringe 1 90 

316. Jewell graphite rheostat 205 

317. Weston's milliamperemeter 207 

318. Cataphoric electrodes 208 

319. Cataphoric outfit without milliamperemeter 209 

320. Arrangement of apparatus for cataphoric work 210 

321. Syringe electrode 213 

322. Flexible face-piece for inhalers 215 

323. Allis's ether inhaler 210 

324-344. Simple cavities in teeth 218-225 

345, 346. Small chisels and hatchet excavators 226 

347. Cavity prepared for filling 227 

348, 349. Cavity near morsal edge of cuspid 227 

350-353. Cavities on mesial and distal surfaces of bicuspids and molars 228 

354-366. Compound cavities 229-233 

367. Water-syringe 241 

368, 369. Burs for opening small cavities 241, 242 

370, 375. Cleavage of enamel 242, 249 

371, 372. Chisels 242, 243 

373. Excavators 245 

374. Instruments for setting screw-posts 248 

376. Crowns restored with cohesive gold-foil 257 

377. Cylinders of gold-foil 258 

378. Foil-carriers 258 

379. Cylinders and mats being introduced into a cavity 258 

380. 381. Bing pluggers ; Butler pluggers 259, 260 

382. Herbst burnishers 262 

383, 384. Varney pluggers ; Webb pluggers 264 

385. Steel mallets 264 

386, 387. Darby-Perry pluggers ; Chappell pluggers 265 

388. Royce plugger-points 265 

389. Snow & Lewis automatic plugger 266 

390. ,391. Abbott automatic mallet 267 

392, 393. Bon will electro-magnetic and mechanical mallets 267 

394, 395. Electric gold annealers 271 

396. Gum retractor 272 

397-401. Clamps for keeping rubber dam in position 272, 273 

402-411. Filling simple cavities upon exposed surfaces 273-276 

412-414. Filling simple approximal cavities 277, 278 

415-429. Filling compound cavities 279-282 

430-433. Matrices and forceps 284, 285 

434. Hand-burnishers 288 

435, 436. Engine-burnishers ; disk burnishers 289 

437. Plug-finishing burs 289 

438. Wood polishing-points 289 

439. Corundum points and wheels 290 

440. Arkansas, Hindostan, and Scotch stones 290 

441. Soft rubber polishing-cups 290 

442^144. Plug-trimmers and finishing files ' 291 

445. Right and left plug-finishing files 292 

446. Thickened- rim sand-paper disks 292 

447. Disk mandrels 293 

448. An inoculated gelatin plate showing antibacteric effects of copper amalgam. . . 313 

449. Creager loop matrices 322 



LIST OF ILLUSTRATIONS. XIX 

FIG. PAGE 

450. Flagg wafering pliers 324 

451. Glass mortar and pestle 324 

452. 453. Amalgam-carriers 326 

454. Flagg amalgam instruments 326 

455. Kirk's instruments for plastics 327 

456. Revised set of amalgam instruments 327 

457. Heating spoon — cone-socket handle 329 

458-461. Built-up molar crowns 330 

462. Flagg' s gutta-percha softener and tool-heater 354 

463. How's thermoscopic heater 335 

464. 465. Glass mixing-slab ; spatulas 338 

466. Details of process for making cast filling for incisor 347 

467^470. Restoration of incisors and molars by cast fillings 348 

471, 472. Bridge-work 349 

473, 474. Porcelain stoppers ; inlay rods 350 

475, 476. Inlay trephines and burs 351 

477, 478. Electric oven ; electric furnace f 352 

479, 480. Erosion of teeth 365 

481, 482. Erosion of teeth from gout 366 

483. Abrasion by tooth-brush 371 

484, 485. Hyperemia of dental pulp 3S0 

486. Secondary growths in pulp-chamber 390 

487, 488. Secondary dentin on wall of pulp-chamber, X 100 390 

489. Secondary dentin in base of pulp-chamber, X 50 391 

490, 491. Pulp-nodules 391 

492. Section of pulp with pulp-nodule, X 70 392 

493. Section of pulp undergoing fibroid degeneration, X HO 392 

494^98. Calcification of dental pulp 393, 394 

499, 500. Osteodentin 395 

501. Bone-tissue in place of resorbed dentin 396 

502-505. Suppuration of dental pulp 408-411 

506. Incisor with enlarged pulp-chamber 414 

507. Pulpitis, X 300 414 

508. Fibrous degeneration of pulp, X 50 415 

509. Metallic caps for capping teeth 418 

510. 511. Sections showing formation of secondary dentin in coronal portion of pulp- 

chamber, X 100 422 

512. Section of pulp treated with arsenic 425 

513. Barbed nerve-broaches 430 

514-525. Longitudinal sections of teeth 432 

526. Peculiarities in cuspids and bicuspids 433 

527-534. Sections of bicuspids, showing pulp-chamber and canals 433 

535-550. Sections of first, second, and third molars 434 

551-557. Abnormalities of dental roots and canals 435 

558, 559. Donaldson bristles ; Gates-Glidden drills 435 

560. Donaldson pulp-cleansers 435 

561, 562. Nerve-extractors 436 

563. Pulp-canal pluggers 439 

564. Canal probe guage 439 

565. Syringe electrode 456 

566. Bleaching electrode 457 

567. Duplex syringe 457 

568. Nipple-expander 458 

569. Bleaching electrode in position 458 

570. Rubber band causing cementitis 460 

571. Dental artery supplying pulp and pericementum 462 



XX LIST OF ILLUSTRATIONS. 

FIG. PAGE 

572. Dunn capillary or drop syringe 463 

573. Metal cap to prevent occlusion 464 

574. Shreddy sac of tooth abscess 476 

575 r 576. Spear-pointed drills ; trephines 484 

577. Puncturing alveolar abscess 484 

578. Rollin circular knives 498 

579. 580. Younger trephines and reamers 499 

581. Eollin spiral knives 499 

582. Ottolengui combined drill and reamer 499 

583. 584. Torsion forceps; bullet forceps * 503 

585. Gooch's double canula snare 503 

586-596. Macroscopic appearances of permanent teeth the roots of which are being 

resorbed 510 

597, 598. Osteoclasts, producing resorption of dental roots '. . . 511 

599, 600. Transverse sections of roots of teeth, near apex, X 175 514 

601-603. Macroscopic appearances of hypercementosed teeth 514 

604, 605. Sections of molar roots, hypercementosis, magnified 514 

606. Transverse section of molar roots, near apex, X 75 515 

607. Transverse section of root of hypercementosed tooth, X 75 515 

608. Transverse section of alveolus and apex of root of abscessed molar, X 96 515 

609. Inostosis, with formation of a pearl-like globule resembling enamel 515 

610. Inostosis, section of root of tooth, X 80 515 

611-614. Necrosis of teeth, macroscopic appearances 520 

615. Epithelial scales and salivary corpuscles from sordes of mouth, X 50 520 

616-619. Salivary calculus 526 

620. Glands of Serres, X 50 526 

621. Small scalers 518 

622. Small rubber disks, wheels, and cups 528 

623. Small revolving brushes 528 

624. Inflamed peridental membrane from a case of pyorrhoea alveolaris, X 50 544 

625. Removing subgingival salivary deposits 546 

626-628. Pyorrhoea alveolaris instruments 547, 548 

629. Medicinal drop syringe 548 

630-632. Splints for supporting loosened teeth 549 

633-636. Gouty pericementitis before and after treatment 563 

637. Underlying condition in pyorrhoea alveolaris 564 

638. Fibroid degeneration of pulp in pyorrhoea alveolaris, X HO 572 

639. Pulp in situ showing calcic degeneration, X 65 572 

640. Hyaline degeneration of the pulp, X 100 573 

641. Colloid degeneration of the pulp, X 21.25 573 

642. Airport's bur ' 576 

643. Improved dento-electric cautery 577 

644. Spray apparatus — hand instrument 578 

645. Spray apparatus — foot instrument 579 

646. Glass tube with capillary point 581 

647. 648. Nitrous oxide apparatus 587 

649-651. Gas-inhalers 588 

652, 653. Hewitt's apparatus for the administration of oxygen with nitrous 

oxide 589, 590 

654, 655. Mouth-props 592 

656. Towel folded as a cone 592 

657, 658. Lente's and Allis's inhalers 593 

659. Aseptible ether inhaler 594 

660. Mouth-mirror 600 

661. Gum-lancet 600 

662. Curved scissors 600 



LIST OF ILLUSTRATIONS. XXI 

FIG. PAGE 

663-665. Mouth-props and gags 601 

666. Laryngeal forceps 601 

667. Turnkey 602 

668. Aseptic forceps 602 

669. Root-elevators , 603 

670. Dental screw 608 

671. 672. Relation of teeth to alveolar processes 604 

673, 674. Superior incisor forceps 604 

675-678. Inferior incisor forceps 605, 606 

679-681. Superior cuspid and bicuspid forceps 606, 607 

682-685. Inferior cuspid and bicuspid forceps 607, 608 

686, 687. Superior first and second molar forceps 609 

688-694. Inferior first and second molar forceps 609-611 

695-697. Superior third molar forceps 611, 612 

698, 699. Inferior third molar forceps 612, 613 

700, 701. Screw-forceps '. . 613 

702-705. Superior root forceps 614 

706, 707. Inferior root .forceps 615 

708. Superior alveolar root forceps 615 

709. Deciduous inferior universal forceps 616 

710. Inferior alveolar root forceps 616 

711. Deciduous superior anterior and root forceps 616 

712. Deciduous superior molar forceps 616 

713. Deciduous inferior anterior and molar forceps 617 

714. Deciduous and superior universal root forceps 617 

715. 716. Common deformities of teeth 617 

717-721. Common malpositions of teeth 617 

722. Skiagraph showing misplaced superior cuspid 617 

723. Misplaced inferior second and third molars 618 

724. 725. Forceps for extracting misplaced molars 618 



PRINCIPLES AND PRACTICE 



OPERATIVE DENTISTRY. 



CHAPTER I. 

CLASSIFICATION AND DESCRIPTIVE ANATOMY OF THE TEETH. 

Nearly all of the mammalia possess a more or less complicated dental 
system. These organs are applied to various purposes, mainly, however, 
to that of procuring food by seizing and killing living prey, or gathering 
and biting off portions of vegetable material, and more indirectly in tearing 
or putting through the hard protective coverings of food substances, such 
as the husks and shells of nuts, or in grinding, crushing, or otherwise 
mechanically dividing the solid materials before swallowing, so as to 
prepare them for digestion in the stomach. Fig. 1 shows the peculiar 
form of the teeth of the mole. 

In many animals certain teeth are excessively developed, and are used 
as weapons of offence and defence ; in others the presence or excessive 
development of certain teeth mark the male sex. 

Man is an omnivorous animal (the term omnivorous comes from the 
Latin omnis, all, and voro, I eat), and, as the term implies, eats all kinds 
of food. He has been endowed by nature with organs of mastication 
suited to the requirements of cutting, tearing, and grinding these various 
forms of food. Man's teeth, therefore, represent in part those of the 
carnivora, or flesh-eating animals, and those of the lierMvora, or vegetable- 
eating animals ; in other words, certain of his dental organs are represent- 
ative of both of these types of animals. The incisors and molars are 
typical of the herbivora, and are suited to cutting and grinding vegetable 
fibre and grains, while the cuspids and bicuspids represent the teeth of 
the carnivora, and are adapted to seizing, tearing, and cutting animal 
food. 

NUMBER AND CLASSIFICATION OF THE TEETH. 

Man, like many others of the mammalia, is endowed with two distinct 
sets of dental organs, one designed to serve the purposes of the economy 
during infancy and early childhood, the deciduous, temporary, or milk 
teeth ; and the other a larger, stronger, and more numerous set, which re- 
places the deciduous teeth, and is designed to serve the purposes of the 
economy from childhood to old age ; these are designated as the permanent 
teeth. 

l 



2 OPERATIVE DENTISTRY. 

The deciduous teeth are twenty in number, ten in each jaw, and are 
expressed by scientists in the following formula : 



I.?? 11 M .22 = 20 

2 2 11 22 

The formula is read as follows, beginning at the median line : incisors* 
two above, two below ; cuspids, one above, one below ; molars, two above, 
two below, which equals ten on either side of the median line, or twenty 
in all. 

Fig. 2. 




Deciduous teeth of the left side. (Gray.) 1 and 2, incisors ; 3, cuspidati ; 4 and 5, molars. 



The permanent teeth of man are thirty-two in number, sixteen in each 
jaw, the formula for which is written thus : 




Permanent teeth of the right side. (Gray.) 1, third molars ; 2, second molars ; 3, first molars ; 4, second 
bicuspidati ; 5, first bicuspidati ; 6, cuspidati ; 7, lateral incisors ; 8, central incisors. 



Beginning at the median line, it reads as follows : incisors, two above, 
two below ; cuspids, one above, one below ; bicuspids, two above, two 




Fig. 1.— Vertical section of inferior maxilla and teeth /// xifu of mole. 



A 



Fig. 4.— Showing structures of a tooth. 
1, enamel ; 2, cementum ; 3, dentin ; 4, pulp- 
chamber. 




Fig. 5.— Occlusion of the teeth. (After Cryer.) 




Cutting i 

Fig. 6.— Superior left central incisor, labial surface. 
(Enlarged.) 




Fig. 7. — Superior right central incisor, labial surface, 
showing short root. ( Enlarged. ) 



CLASSIFICATION AND DESCRIPTIVE ANATOMY OF THE TEETH. 3 

below ; molars, three above, three below, equals sixteen on either side of 
the median line, or thirty-two in all. 

The ten anterior permanent teeth of each jaw are sometimes called the 
teeth of replacement, or succedaneous teeth, from the fact that they replace 
the deciduous teeth. The permanent incisors and cuspids take the place 
of the temporary teeth of the same name, while the bicuspids assume the 
positions occupied by the temporary molars. The permanent molars 
appear one by one behind the position occupied by the second deciduous 
molars. 

DESCRIPTIVE ANATOMY OF THE TEETH. 

The teeth are specialized organs of mastication implanted within the 
alveolar processes of the superior and inferior maxillce in man and in many 
animals. The teeth are composed of five tissues (Fig. 4) : a vitreous-like 
substance which comj)letely covers the crown — the enamel (1) ; a bone-like 
substance which envelops the root — the cementum (2) ; and a hard substance, 
less dense than enamel but harder than bone, which forms the interior or 
body of the organ — the dentin (3) ; while a small mass of soft tissue occu- 
pies a central cavity (4) within the crown and the root — the pulp ; and a 
fibrous membrane covers the cementum of the root — the pericementum. 

In a normally developed individual of the genus homo the teeth are 
arranged in the form of two parabolic or elliptical curves, the superior 
arch describing a trifle larger curve than the inferior, so that the teeth of 
the former slightly overreach their antagonists in the latter. The buccal 
cusps of the upper bicuspids and molars close over the buccal cusps of the 
lower teeth ; this brings the buccal cusps of the lower teeth within the 
sulci of the upper, and the palatal cusps of the upper teeth within the 
sulci of the lower. The incisors, cuspids, and bicuspids of the lower jaw 
are smaller than the corresponding teeth in the upper, the greatest differ- 
ence being in the size of the incisors. The superior incisors and cuspids 
are slightly longer than the inferior and overlaid them, while the cuspids 
and molars not only overreach their opposites in the inferior maxilla, but 
so interlock at their occlusal surfaces that each tooth, except the third 
superior molars, occludes or antagonizes with two of its fellows in the 
opposite jaw, when the teeth are brought into their normal occlusion. (Fig. 
5.) This arrangement permits the whole of the occlusal surfaces of these 
teeth to be brought into contact by the various movements of the jaws in 
mastication, thus rendering the function of triturating the food and pre- 
paring it for digestion most effective. 

A normal incisor tooth presents certain characteristics which are com- 
mon to all the dental organs of man ; it will therefore serve the purpose of 
illustrating the anatomical divisions of the teeth, which are as follows : the 
crown, the cervix, the root, the pulp -chamber, the pulp-canal, the morsal* or 
cutting edge, the apex, and the apical foramen. A more minute description 
relative to the cusps, surfaces, angles, margins, grooves, fissures, etc., will 
be reserved for the special anatomy of the individual teeth. 

* The term morsal is used, following the suggestion of Dr. Thompson, in the place 
of incisive or cutting edge and occlusal surface. 



4 OPERATIVE DENTISTRY. 

The crown is that portion of the tooth which is visible within the 
mouth, projecting beyond the gum ; the cervix or neck is that part repre- 
sented by a constriction between the crown and the root at the point where 
the enamel and the cementum meet, or, in other words, the portion grasped 
by the margin of the gum ; the root is that part which is implanted within 
the alveolar process of the jaw and covered by the gum ; the morsal edge or 
cutting edge is that portion of the crown which occludes or antagonizes 
with a tooth in the opposite jaw ; the apex is the terminal end of the root, 
that portion farthest removed from the crown (Fig. 6) ; the pulp- chamber 
is a cavity or cul-de-sac located within the crown, and may be termed a 
coronal enlargement of the pulp-canal which extends through the centre 
of the root from its apex to the pulp-chamber within the crown ; the apical 
foramen is the orifice or entrance to the pulp-canal located in the apex of 
the root. 

ARCHITECTURAL DESIGN OF THE TEETH. 

It is important to the dental student that he understand and appreciate 
the architectural design upon which nature has constructed the dental 
organs. The more closely he studies this design, in both their gross and 
minute anatomy, the more will he become impressed with the perfection 
of the general plan and the admirable adaptation of their form, their 
structure, and their tissues to perform the functions for which they were 
created. 

The form of the teeth is designed upon the plan of the cone, modified 
to meet the individual requirements of the several classes of teeth ; some 
are composed of a simple cone, like the incisors and cuspids, while others 
are a combination of two or more cones, as in the bicuspids and molars. 
In no way can these facts be taught so well as by modelling in clay the 
forms of the various classes of teeth, commencing with the sinrple forms 
as expressed in the single-rooted teeth, and progressing to the more com- 
plex through a series of double and multiple cones in the formation of the 
bicuspids and molars. 

THE INCISORS. 

There are eight incisor teeth in the dental series of man, four in the 
upper jaw and four in the lower, two situated upon either side of the 
median line of the jaw ; the first are termed the central incisors, and those 
next in order upon the distal side of the centrals are known as the lateral 
incisors. 

The situation of the central incisors in the extreme anterior portion of 
the jaw upon opposite sides of the median line causes their mesial sur- 
faces to approximate each other. 

The function of the incisor tooth is to cut or incise the food, — hence its 
name, which is derived from the Latin, incido, to cut. 

These teeth are all designed upon the form of the truncated cone, with 
slight modifications, to meet the requirements of the individual organ. 

The Superior Central Incisor. — This tooth is in form a modified 
truncated cone with its base flattened out to form the morsal or cutting 
edge. It presents for examination four surfaces, — labial, lingual, mesial, and 



CLASSIFICATION AND DESCRIPTIVE ANATOMY OF THE TEETH. 5 

distal; two angles, — mesial and distal; and a morsal edge. The general 
form of the crown is that of the wedge or chisel, the edge being quite 
thin, the angles rounded, and the thickness rapidly increasing to the cer- 
vix of the tooth. It is also slightly curved from the cervix to the morsal 
edge, and curved over mesio-distally, so that the labial surface is somewhat 
convex and the palatal concave. 

The labial surface (Fig. 7) of the crown is in general outline an imper- 
fect quadrilateral, the cervical margin being rounded. Tins surface has 
four margins, — mesial, distal, cervical, and morsal or incisive. (Fig. 8.) 

The mesial margin begins at the morsal margin or cutting edge, and 
extending upward, usually with a slight distal inclination, unites with 
the cervical margin. The distal margin also begins at the morsal mar- 
gin, and extends upward with a slight mesial inclination, uniting with 
the cervical margin. Both of these margins are more or less convex. 
The cervical margin is somewhat rounded, the form following the outline 
of the gingival border, where it unites with the mesial and distal mar- 
gins. The morsal margin extends from the mesial margin to the distal 
margin. 

The union of the mesial and morsal margins form the mesial angle, 
while the union of the distal and morsal margins form the distal angle. 
The mesial angle is usually pointed and square, while the distal is much 
more obtuse. Two shallow grooves or depressions — the labial grooves— 
traverse the labial surface in a longitudinal direction, dividing it into 
three lobes, the mesial, median, and distal. These grooves extend from the 
morsal edge to the middle or upper third of the labial surface, where they 
broaden out and disappear. They are termed developmental lines (Black), 
and represent the three primitive plates of calcification in the develop- 
ment of the tooth, the grooves being formed by the union of these plates 
with each other. Occasionally one or more transverse ridges are found 
upon the cervical portion. 

The lingual surface (Fig. 9) of the crown is triangular in outline, smaller 
than the labial surface, and presenting a more or less angular concavity, 
the lingual fossa. This fossa is bounded by three marginal ridges and the 
morsal or cutting edge. 

The mesio-marginal ridge extends from the mesial angle upward to the 
cervico-marginal ridge, following the curvature of the mesial margin. 

The disto -marginal ridge extends from the distal angle to the cervico- 
marginal ridge, following the curvature of the distal surface. 

The cervico-marginal ridge forms -a curved line at the cervix or base of 
the crown, uniting by its extremities with the mesial and distal marginal 
ridges. The marginal ridges are often high and conspicuous, and the 
cervico-marginal ridge is sometimes developed into a cusp, the ridge at 
the base forming a girdle or cingulum. The lingual fossa is usually 
smooth, but occasionally it forms a deep depression or pit, while a fissure 
may extend from it into the cervico-marginal ridge. Two longitudinal 
grooves are sometimes seen traversing the lingual fossa, which correspond 
to the developmental grooves upon the labial surface. 

The Mesial and Distal Surfaces. — The outlines of these surfaces (Figs. 



b OPERATIVE DENTISTRY. 

10 and 11) are irregular triangles, with the base directed towards the root 
and the apex terminating at the incisive or morsal edge. The base of the 
triangle is concaved at the cervical margin, and the apex rounded or con- 
vex at the morsal edge. 

These surfaces have three margins, — labial, lingual, and cervical. The 
mesial surface is slightly longer than the distal surface, and presents a 
more or less convex and rounded form, slightly flattened near the cervical 
margin. 

The distal surface is rounded as in the mesial, but more curved in its 
longitudinal axis. The labial margins of these surfaces are convex, 
following the outline of the labial surface, while the lingual and cervical 
margins present concave outlines, following the curves of the lingual 
surface, and the cervical line. 

The incisive edge or morsal margin of the crown is formed by union of 
the labial and lingual surfaces, and extends in a nearly straight line 
from the mesial to the distal surface, with a slight downward pitch 
towards the median line. In a recently erupted tooth this line is often 
broken by the presence of the developmental grooves ; these, however, 
soon disappear with use, leaving the line comparatively straight. In a 
normal occlusion these teeth shut over the lower incisors, but occasion- 
ally they will be found to occlude squarely with their fellows of the lower 
jaw. 

The cervix or cervical line or margin is clearly and distinctly marked by 
the free extremity of the enamel which covers the crown of the teeth. The 
termination of the enamel at the neck of the tooth marks the extent of the 
peridental membrane. The enamel edge, which slopes off more or less 
abruptly to meet the cementum, does not form a straight line around the 
tooth, but curves upward upon the root at the labial and lingual surfaces 
and downward at the mesial and distal surfaces, thus forming in outline a 
double convexity and a double concavity. 

The root in section of the tooth at the cervix shows it to be broader 
on the labial than the lingual surface, — pear-shaped, — and this condition 
is maintained throughout the greater length of the root. 

In general outline the root has the form of a slender cone. The aver- 
age length of the superior central incisor is 0.88 inch (2.23 centimetres), 
of the crown 0.39 inch (0.99 centimetre), and of the root 0.49 inch (1.24 
centimetres).* 

The pulp-chamber is large, and the pulp-canal usually gives free access 
to the apex. In young teeth the cornua extend well towards the angles, 
while in old persons the pulp-chamber and canal is often constricted, 
making it difficult of access. 

The Superior Lateral Incisor. — This tooth is the second in the 
dental arch from the median line, and approximates the central incisor 
upon its distal surface. It is a little shorter, and about a third narrower 
than the central incisor, has the same general form and architectural 
design, and is possessed of the same developmental grooves. 

* All measurements of the teeth are taken from Black's Dental Anatomy. 




Cervical 

margin Cervico- 

rnarginal 

ridge 



Distal 
margin 



Distal 
angle 



Disto- 

marginal 

ridge 



Mesial 
angle 



Morsal edge Labial grooves 

Fig. 8. — Superior left central incisor, labial surface. 




(Enlarged.) 



Lingual fossa 
-Superior left central incisor, lingual surface. 
(Enlarged.) 





Fig. 10.— Superior left central incisor, mesial surface. 
(Enlarged.) 



Fig. 11. — Superior left central incisor, distal surface. 
(Enlarged.) 




^atrial grooves Morsal edge 

Fig. 12. — Superior right lateral incisor, labial surface. Fig. 13. — Superior right lateral incisor, lingual surface. 
(Enlarged.) (Enlarged.) 





Fig. 15.— Superior right lateral incisor, mesial surface. Fig. 16.— Superior right lateral incisor, distal surface. 
(Enlarged.) (Enlarged.) 



CLASSIFICATION AND DESCRIPTIVE ANATOMY OF THE TEETH. 7 

The crown presents for examination four surfaces, labial, lingual, mesial, 
and distal ; a cervical margin, an incisive or morsal edge, a mesial and a distal 



The labial surface of the crown (Fig. 12) is more rounded than in the 
central, the mesial angle is acute, and the morsal edge slopes upward to a 
rounded and obtuse distal angle. The mesial half of the crown seems to 
partake of the form of the central incisor, while the distal half approaches 
the form of the cuspid. In the young tooth the morsal edge, as in the cen- 
tral, presents three tubercles, more or less distinct, with the developmental 
grooves passing between them. 

The lingual surface (Fig. 13) in a majority of instances is the broadest 
part of the crown. It is less concave than in the central, but more de- 
pressed at the base of the cervical ridge. The mesial and distal marginal 
ridges are in proportion to the size of the tooth, broader and stronger 
than in the centrals. The cervical ridge is also well marked and propor- 
tionately broader and stronger than in the central. 

Occasionally, however, the marginal ridges are but slightly developed ; 
the surface is then quite smooth. The lingual fossa may be divided by a 
longitudinal ridge with slight depressions upon either side between it and 
the marginal ridges. The cervical ridge is sometimes very prominent, 
forming a cingulum, at the centre of which a tubercle is often developed. 
An exaggerated development of this cusp or cingule 
is shown in Fig. 14, a, from a case reported by W. H. 
Mitchell. 

As a consequence of this greater prominence of the 
cingulum, and the marked depression or pit so often 
found at its base, caries is more liable to occur upon 
the lingual surfaces of the superior laterals than upon 
those of the central incisors. 

The mesial and distal surfaces (Figs. 15 and 16) 
present a triangular or V-shaped outline similar to that 
of the central incisor. The mesial surface is rounded near the morsal 
edge, but considerably flattened near the cervix. A slight depression 
sometimes exists at this point, while the mesio-labial angle occasionally 
presents a flattened or depressed point midway between the morsal edge 
and the cervix. The distal surface is convex in all directions, and quite 
full at the morsal or incisive third ; from this point it slopes towards 
the cervical line, where it becomes quite flat. 

The morsal edge is divided into two parts by a more or less prominent 
tubercle. The mesial half is straight, like that of the central, while the 
distal half has a slight upward slope, terminating in a rounded distal 
angle. When the tubercle becomes worn off, the edge is straight, with a 
pitch towards the median line. 

The cervix is considerably flattened mesio-distally. Section of the root 
at this point shows the form to be a flattened oval. The cervical line 
follows the same course as in the central incisor, having an upward curve 
upon the labial and lingual surfaces, and a downward curve upon the 
mesial and distal surfaces. 




8 OPERATIVE DENTISTRY. 

The enamel margin does not, as a rule, end so abruptly as in the central 
incisors, although occasionally it will end in a sharply defined ridge. 

The root of the tooth is conical, but more or less flattened mesio- 
distally ; its labio-lingual diameter at the neck is about one-third greater 
than its mesio-distal diameter. The root is generally straight, but in many 
specimens the apex has a slight distal curvature. Occasionally it is very 
crooked. The average length of the superior lateral incisor is 0.85 inch 
(2.15 centimetres), of the crown 0.34 inch (0.86 centimetre), and of the 
root 0.51 inch (1.29 centimetres). 

The lateral incisors are the most variable in size and form of all "ie 
dental series of man, and they more frequently fail to appear in the dental 
arch— suppressed— than any others except the third molars. They are often 
imperfectly developed, and not infrequently present a conical or peg- 
shaped form. In one instance which has come under the observation of 
the writer, the superior lateral incisors have been absent in certain mem- 
bers of a family for three generations. The father had never erupted 
these teeth, his only daughter had the same deformity, and of her four 
children, two boys and two girls, the eldest son and both daughters have 
never erupted them, while these teeth in the second son are developed and 
peg-shaped. 

The pulp-canal partakes of the shape of the root, which is generally 
flattened, and when the root is straight it can be readily entered and fol- 
lowed to the apex ; but in operating for the removal of the pulp, the 
possibility of encountering a root with a curved apical end must not be 
overlooked. 

THE LOWER INCISORS. 

The lower incisors have the general outlines of the superior laterals, but 
they are in every way smaller, the roots are much more flattened mesio- 
distally, and often have a groove upon the mesial and distal surfaces run- 
ning from the cervix to the apex. 

The labio-lingual diameter of the root is much greater than its mesio- 
distal diameter. They are located in the anterior portion of the lower jaw 
upon either side of the median line, opposite the superior incisors, with 
which they occlude in cutting food. The developmental lines are the 
same, but the tubercles upon the morsal edge and the labial grooves are 
less strongly marked than in the superior incisors. 

The lower central incisor is the smallest tooth of the dental series of 
man. It is chisel-shaped in form. The crown, viewed mesio-distally and 
labio-lingually, is composed of a double wedge. The widest portion of the 
crown is the morsal edge, which is thin and straight. From this point it 
slopes slightly to the cervix, where it is only about one-half as wide as at 
the edge. 

The labial surface (Fig. 17) has the outline of a slender wedge, its widest 
portion at the morsal edge, and its narrowest at the cervix. It is nearly 
straight, or only slightly convex near the edge, but as it approaches the 
cervix it becomes more rounded and convex. The cervical margin is well 
defined and concave towards the root. The mesio-labial and disto-labial 



!>abial grooves 




Fig. 17. — Inferior right central incisor, 
(Enlarged.) 



riuiit central incisor, lingual surface. 
(Enlarged.) 




right central incisor, 
(Enlarged.) 




Fi<;. 20.— Infcri. 



right central incisor, di 
(Enlarged.) 








Mesio- 

narginal 

ridge 


-M , v .-^_ 


Lingual 
fossa 







Disto- 

marginal 

ridge 



Fig. 21. — Inferior right lateral incisor, labial surface. 
(Enlarged.) 



Fig. 22. — Inferior right lateral incisor, lingual surface. 
(Enlarged.) 





Fig. 23. — Inferior right lateral incisor, mesial surface. 
(Enlarged.) 



Fig. 24.— Inferior right lateral inciapr, distal surface. 
(Enlarged.) 



CLASSIFICATION AND DESCRIPTIVE ANATOMY OF THE TEETH. 9 

margins are rounded off at the expense of the labial surface. The mesial 
angle is quite acute, and the distal angle slightly obtuse and rounded. 

The lingual surface (Fig. 18) is concave from the mesial edge to the cervix, 
but is nearly flat, or only slightly concave mesio-distally. The marginal 
ridges are not strongly marked. 

The mesial and distal surfaces (Figs. 19 and 20) are V-shaped in outline, 
with the apex directed towards the morsal edge of the crown. They are 
convex near the edge, but become flattened and even slightly concave at 
the cervix. 

The cervix is flattened mesio-distally, the greatest diameter being the 
labio-lingual. Section at this point gives the form of a compressed oval. 

The root is flattened like the cervix, for its entire length. The apex 
sometimes has a distal curve. The groove upon the mesial and distal 
surfaces is sometimes quite deep and occasionally results in bifurcation. 

The pulp canal is thin and flattened, partaking of the form of the root ; 
in some instances it is with great difficulty that the canal can be entered 
with the most delicate instruments. The average length of the inferior 
central incisor is 0.81 inch (2.05 centimetres), of the crown 0.34 inch (0.86 
centimetre), and of the root 0.47 inch (1.19 centimetres). 

The inferior lateral incisor (Figs. 21, 22, 23, and 24) is similar in 
form to the inferior central, but, unlike the superior incisors, it is distinctly 
larger than the centrals, not only in width of crown, but also in the length 
of the root, while the marginal ridges are more strongly marked and the 
fossa more distinct. The morsal edge has a slight distal pitch, and the 
distal angle is obtuse and rounded. 

The average length of the inferior lateral incisors is 0.85 inch (2.15 centi- 
metres), of the crown 0.35 inch (0.88 centimetre), and of the root 0.50 
inch (1.26 centimetres). 

THE CUSPIDS. 

There are four cuspids in the dental series of man, two in each jaw. 
They are situated just in front of the angle of the mouth, between the 
lateral incisor and the first bicuspid tooth ; they are the third in order 
from the median line, and form the spring of the superior dental arch. 
These teeth are variously known as cuspids, cuspidati, canines, and eye- 
teeth. The term cuspid comes from the Latin cuspis, a point. 

The cuspid teeth are in all respects larger and stronger than the 
incisors, the crown is thick and spear-pointed, and the root long and 
heavy. 

The architectural form of these teeth adapts them for seizing, piercing, 
and tearing animal food, and they represent the carnivorous element in 
man. 

The Superior Cuspids. — The crowns of the superior cuspids present 
for examination four surfaces, the labial, lingual, mesial, and distal, two 
margins, the cervical and morsal, and two angles, the mesial and the distal. 
The general outline of the crown is that of a short cone with its base 
at the gum line, and it represents the primitive conical teeth of many of 
the fishes. 



10 OPERATIVE DENTISTRY. 

The labial surface (Fig. 25) of tlie crown in outline is spear-shaped. It 
is convex in all directions, and is much more rounded mesio-distally than 
the incisors. The developmental grooves and ridges are often quite promi- 
nent. The distal groove is usually most strongly marked, which brings 
the central and distal lobes into greater prominence. This surface is 
bounded by five margins, the mesial, distal, cervical, mesio-morsal, and 
disto-morsal. 

The mesial and distal margins are rounded and convex from the morsal 
edge to the cervical margin ; the convexity being greatest in the distal 
margin. The distal margin is slightly shorter than the mesial on account 
of the sharper slope of the disto-morsal edge. 

The cervical margin follows the contour of the gum line, and unites 
with the mesial and distal margins. 

The morsal margin is divided by a prominent cusp, from the summit of 
which gradually slope away the mesio-morsal and disto-morsal margins. 

The mesio-morsal margin slopes slightly upward, and is usually a trifle 
concave, though occasionally it is convex. 

The disto-morsal margin may be described in the same manner, except 
that it is a little longer, and has a slightly more pronounced upward slope 
and a deeper concavity. The widest part of the labial surface is at a line 
drawn from the mesial to the distal angles ; the narrowest part is at the 
cervical margin. 

The Ungual surface (Fig. 26) presents nearly the same general outline of 
the labial surface, with the exceptions that it is more fiat, sometimes concave, 
and has three generally well-defined marginal ridges. The mesio-marginal 
and disto-marginal ridges arise at the mesial and distal angles, and pass 
upward, where they unite with the cervico-marginal ridge, which may be 
said to be formed by the union or continuation of the two former ridges. 
The cervico-marginal ridge is sometimes quite prominent, terminating in a 
more or less pronounced tubercle or cusp. Between the mesio- and disto- 
marginal ridges there is a prominence known as the lingual or triangular 
ridge, upon either side of which are sometimes deep fossa or fissures, but 
more frequently they are shallow and ill-defined. 

The mesial surface (Fig. 27) resembles that of the central incisor in many 
respects. It is convex in all directions at the mesial angle, but as it ap- 
proaches the cervix it becomes flattened and occasionally concave. 

The distal surface (Fig. 28) in general outline is similar to the mesial 
surface, except that it is more rounded, and, as it nears the cervix, not 
quite so flat. The distance from the cervix to the distal angle is nearly 
one-third shorter than the distance on the mesial surface from the cervix 
to the mesial angle. 

The morsal edge by its form gives to the cuspid tooth a double function, 
that of incising and penetrating. The morsal edge combines a cusp which 
is placed near the centre, to the long axis of the tooth, and two cutting or 
incisive edges which slope away from it in an upward direction, and termi- 
nate at the mesial and distal angles. The distal edge is longer than the 
mesial, and it has a more acute upward slope. The sharp cusp is soon 
worn off, and in old age the morsal edge may be reduced to a straight line. 




Disto 
mor 

margin 



Morsal margin 
-Superior right cuspid, labial surface. 
(Enlarged.) 




Fig. 26.— Superior right cuspid, lingual surface. 
(Enlarged.) 





Fig. 27. — Superior right cuspid, mesial surface. 
(Enlarged.) 



Fig. 28. — Superior right cuspid, distal surface. 
(Enlarged.) 



Disto- 
morsal 

edge 

Distal 
angle 

Cervical 

margin 






M 







edge 

Mesial 
angle 

Labial 

ridge 

Cervical 
ridge 




-Inferior right cuspid, labial surface. 
(Enlarged.) 



-Inferior right cuspid, lingual surface. 
(Enlarged.) 




Fig. 31.— Inferior right cuspid, mesial surface. 
(Enlarged.) 




-Inferior right cuspid, distal surface. 
(Enlarged.) 



CLASSIFICATION AND DESCRIPTIVE ANATOMY OF THE TEETH. 11 

The cervix on section presents a flattened oval. The enamel line 
maintains about the same outline as in the central incisors, curving 
upward upon the labial and lingual surfaces, and downward upon the 
mesial and distal. Occasionally it presents a slight depression both 
mesially and distal^, which may be continued upon the root as a groove. 

The root is the longest of all the human teeth, and is irregularly coni- 
cal in form, tapering to a slender point ; it is usually straight, but may be 
curved or very crooked. In size it is about one-third larger than the 
central incisor. It is flattened slightly mesio-distally, and occasionally 
grooved. 

The pulp-canal is large and accessible, usually of the same form as the 
root, and except when the root is curved or crooked, can be easily followed 
to its apex. 

The average length of the superior cuspid is 1.05 inches (2.66 centi- 
metres), the average length of the crown is 0.37 inch (0.94 centimetre), 
and of the root 0.68 inch (1.72 centimetres). 

The Inferior Cuspids. — There is probably a greater similarity be- 
tween the superior and inferior cuspids than between any other class of 
teeth in the human mouth. They are alike in form and outline, though 
the inferior are somewhat smaller. The crowns are a little longer, and this 
makes them appear more slender ; they are also more flattened mesio-dis- 
tally at the cervix and in the root. These teeth are heavily built and 
firmly set in their alveoli, in order to enable them to perform the double 
function of incising and tearing food. The cusp is generally more promi- 
nent and pointed than in the superior cuspids. The crown opposes the 
mesial surface of the superior cuspid and the distal surface of the superior 
lateral incisor. 

The labial surface (Fig. 29) of the crown is smooth and convex, the de- 
velopmental grooves are less prominent than in the superior cuspids ; the 
labial ridge, however, is well developed, and extends from the cusp to the 
cervical margin, giving additional strength to the crown. Transverse 
ridges are also occasionally present in the cervical region. To accommo- 
date the occlusion of the superior teeth, the labial surface of the crown is 
inclined inward. 

The lingual surface (Fig. 30) is quite smooth, the ridges and grooves 
being less strongly marked than in the superior cuspids. The lingual 
ridge, which extends from the cusp to the cervical ridge, is, however, 
sometimes quite prominent. In exceptional cases the cervical ridge is 
strongly developed, forming a fossa at its base. 

The mesial surface (Fig. 31) is rounded at the eminence, flattened at the 
cervical third, and nearly straight with the surface of the root, which gives 
the crown the appearance of being bent backward or having a distal in- 
clination. 

The distal surface (Fig. 32) is quite convex and the disto-morsal angle 
prominent ; as it approaches the cervix it becomes more or less flattened, 
and at the cervical margin may present a slight concavity. 

The morsal edge presents a more or less prominent cusp and a mesial 
and a distal incisive edge. The distal edge is longer than the mesial, and 



12 OPERATIVE DENTISTRY. 

slopes away rapidly to the distal angle. The differences, however, are not 
so marked as in the superior cuspids. The angles are pronounced, but the 
mesial less so than the distal. 

The cervix is generally found on section to be oval in form, although 
sometimes it is flattened mesio-distally, and when the root is grooved it 
may present a modified hour-glass outline. The curves of the enamel line 
are not so variable as in the incisors, nor the termination of the enamel 
quite so abrupt as in the superior cuspids. 

The root is long, straight, tapering, and flattened mesio-distally. It is 
shorter than the superior cuspid, and not infrequently presents a decided 
depression or groove upon its mesial and distal surfaces, showing a ten- 
dency towards bifurcation. The apex is slender and sometimes curved in a 
labial direction. 

The pulp-canal has the same general outline as the root, and when the 
longitudinal grooves upon the mesial and distal surfaces are deep, the canal 
is constricted in the middle, making it more or less difficult to enter with 
instruments. The average length of the inferior cuspids is one inch (2.53 
centimetres), of the crown 0.40 inch (1.01 centimetres), and the root 0.60 
inch (1.52 centimetres.) 

THE BICUSPIDS. 

The bicuspids, or premolars, as they are sometimes termed, are the fourth 
and fifth teeth from the median line, and are situated between the cuspid 
and first molar teeth. There are eight bicuspids in a normal denture of 
man, two upon each side in the upper and lower jaws. The one which 
is situated next to the cuspid tooth is termed the first bicuspid, and the one 
located between the first bicuspid and the first molar is known as the second 
bicuspid. The term bicuspid is derived from the Latin bi, two, and cuspis, a 
point, — two-pointed or bi-cusped ; a tooth, therefore, with two cusps. 

Architecturally the bicuspid tooth is formed of two cones fused together. 
This structure, from the mechanical stand-point, is weak and faulty, as its 
power of resistance to the mechanical force applied in mastication depends 
upon the strength of the mesial and distal marginal ridges which bind the 
cones together upon the morsal surface ; when these for any reason have 
been destroyed, the greatest weakness of the structure is developed, ending 
in the separation of the cones under stress and the loss of one or both cusps. 
Fractures of this character occur more frequently in the bicuspids on 
account of their mechanical weakness than in any of the other teeth. 

The bicuspids succeed and replace the deciduous molars, and by reason 
of their smaller size give extra space in the jaws for the permanent cuspids, 
which are much larger than their deciduous predecessors, and are, as a 
rule, erupted at a later period. 

The function of the bicuspids is to divide the food into small pieces 
and prepare it to be triturated by the molars. 

The superior first bicuspids, viewed from the morsal surface, have 
the form of a rounded quadrilateral, the buccal margin being broader than 
the lingual. Section through the crown just beyond the cusps shows a 
somewhat pear-shaped outline. The design of this form is to make it pos- 





iperior right first bicuspic 
(Enlarged.) 



Lingiuu cusp 
'M. — Superior right first bicuspid, lingual surface. 
(Enlarged.) 




Lingual cusp 
Fig. 35.— Superior right first bicuspid, mesial surfac 
(Enlarged.) 




Fig. 36. — Superii 



Buccal cusp 
right first bi'cuspi< 
(Enlarged.) 



Buccal triangular ridge 





Fig. 37. — Superior right first bicuspid, morsal surface. 
(Enlarged.) 



-Superior right second bicuspid, buccal 
surface. (Enlarged.) 




Lingual cusp 
-Superior right second bicuspid, lingual 
surface. (Enlarged.) 




Fig. 40. — Superior right second bicuspid, mesial 
surface. (Enlarged.) 



CLASSIFICATION AND DESCRIPTIVE ANATOMY OF THE TEETH. 13 

sible for these teetli to follow the curve of the alveolar arch. The bucco- 
lingual diameter of the crown is about one-third greater than its raesio- 
distal diameter. 

The buccal surface (Fig. 33) of the crown is almost a counterpart of 
the corresponding surface of the superior cuspid, with the exception that 
the cusp is placed nearer the centre of the crown, thus making the mesial 
and distal morsal margins nearly of the same length. The central or 
buccal ridge which springs from the cusp is prominent, while the mesial 
and distal ridges or lobes are rarely conspicuous. The developmental 
grooves or furrows between them are, therefore, shallow and extend only 
about half-way to the cervix, where they are lost in the smooth convexity 
of the cervical half of this surface. The surface is considerably narrower 
at the cervical margin, which gives it the general outline of a cone, with 
the apex at the cervical margin. This difference in the width of the 
buccal surface at the angles and at the cervix gives the -'bell-shaped" 
form to these teeth. 

The Ungual surface (Fig. 34) is mesio-distally regularly convex. From 
the lingual cusp to the cervix it presents a nearly straight line, though 
many times it is slightly convex, and occasionally fully as much so as the 
buccal surface. Mesio-distally the surface is not so broad as the buccal 
surface, and the lingual cusp is not quite so long. 

The mesial surface (Fig. 35) bucco-lingually is much flattened, but 
slightly convex ; from the mesio-morsal marginal ridge to the cervix it is 
also slightly convex, although examples are numerous in which a shallow 
concavity is presented at the cervical margin, which extends to the side 
of the root in a more or less sharply defined groove. The marginal angles 
formed by the union of this surface with the buccal and morsal surfaces 
are well defined, but the mesial and lingual surfaces are so blended and 
rounded that it is difficult to designate their line of union as an angle. 

The distal surface (Fig. 36) is so nearly like the mesial surface that it 
needs no especial description except in the points of difference. It is 
rather more convex than the mesial surface, has rarely a convexity at the 
cervical margin, and the disto-morsal angle is more prominent than the 
mesio-morsal. 

The morsal or occlusal surface (Fig. 37) presents an abrupt change in 
form and function as compared with the morsal edge of the cuspid tooth. 
This surface is composed of two well-defined cusps or points divided by 
a deep sulcus having a mesio-distal direction, and bound together at their 
bases mesially and distally by two strong and prominent ridges termed the 
mesio-morsal and the disto-morsal ridges. 

One of these cusps is situated at the buccal margin, and the other at the 
lingual, and from their situation are designated as the buccal and the lingual 
cusps. The buccal cusp is usually sharper, longer, and more prominent 
than the lingual cusp. The lingual cusp is broader and more rounded. 
From the summit of the buccal cusp four ridges slope away at right angles, 
one mesially to form the mesio-morsal edge of the crown ; one distally to 
form the disto-morsal edge ; one to the buccal surface, forming the central 
buccal ridge, and another slopes downward in an opposite direction to form 



14 OPERATIVE DENTISTRY. 

the buccal triangular ridge, which ends either in the central sulcus or joins 
a similar ridge descending from the summit of the lingual cusp, and forms 
the transverse ridge. The mesio-morsal aud disto-morsal edges enter into 
the formation of the mesial and distal morsal angles at their extremities. 

The lingual cusp is usually blunt, and its margins, which are not sharply- 
defined, unite with the marginal ridges at both angles. The lingual trian- 
gular ridge arises at the summit of the lingual cusp, and either terminates 
at the central sulcus or joins its fellow of the buccal cusp to form the trans- 
verse ridge. The lingual triangular ridge is seldom prominent, and some- 
times is entirely absent. 

The central sidcus extends from one lateral rid°:e to the other in a mesio- 

;tal direction, and widens into the mesial a 

The mesial and distal sulci are not alwayi 
passing over the central portion of the mesial and distal marginal ridges. 
The mesial and distal triangular grooves are situated at the base of the 
marginal ridges, and are directed towards the mesial and distal angles, 
dividing the marginal ridges from the triangular, where they are either 
lost or may be traced as slight depressions near the angles. These sulci 
often become the seat of caries. 

The cervix is flattened laterally, its bucco-lingual diameter being some- 
what greater than its mesio-distal. The enamel line curves slightly 
upward at the buccal and lingual cervical margins, and dips downward a 
very little, or may describe a nearly straight line at the mesial and distal 
cervical margin. 

The root is considerably flattened laterally, and is generally more or 
less deeply grooved from the cervix to the apex, and often bifurcated for 
from one-third to two-thirds of its length. The root over the buccal cusp is 
the buccal root, and that over the lingual cusp is termed the lingual root. 

Bifurcated roots in the first superior bicuspid is the rule in the negro 
and other races of a low order of intelligence, and also in the apes. It is 
often very crooked, or may be triple-rooted. 

The pulp-canal usually takes the form of the root, and may be either 
single or double. It is narrow at the neck, and often constricted in the 
middle, giving it the outline of an hour-glass. More often, however, it 
has two distinct pulp -canals. The coronal portion of the canal terminates 
in two well-defined cornua or horns which point towards the cusps of 
the crown. 

The average length of the first bicuspid is 0.80 inch (2.03 centimetres), 
of the crown 0.32 inch (0.81 centimetre), and of the root 0.48 inch (1.21 
centimetres). 

The superior second bicuspid so nearly resembles the first that its 
differences only need to be noticed. It is in every way a little smaller ; 
the cusps are reduced, while the lingual cusp equals or exceeds the buccal 
cusp in size and length. The marginal ridges are broader, and the morsal 
surface more flattened, and often presents several shallow wrinkles or 
supplemental grooves and ridges, which radiate from the central sulcus. 
The triangular ridges are often united, thus increasing the strength of the 
tooth. The crown is narrower mesio-distally, and the cervix more oval, 



Buccal cusp 




Fig. 41.— Superior right second bicuspid, distal 
surface. (Enlarged.) 



Lingual cusp 
Fig. 42. — Superior right second bicuspid, morsal 
surface. (Enlarged.) 



Buccal ridge 



Transverse ridg< 





Fig. 43. — Inferior right first bicuspid, buccal surface. 
(Enlarged.) 



-Inferior right first bicuspid lingual surface. 
(Enlarged.) 



angular or transverse ridge 




Buccal cusp 



Lingual Disto- 

cusp morsal 

ridge 




Fig. 45. — Inferior right first bicuspid, mesial surfaei 
(Enlarged. ) 



Fig. 46. — Inferior right first bicuspid, distal surface. 
(Enlarged.) 



Buccal cusp 



Buccal cusp 




ridge 



ridge 



Lingual ridge or cusp 
Fig. 47. — Inferior right first bicuspid, morsal surface. 
(Enlarged.) 




Lingual groove 
Fig. 48.— Inferior right second bicuspid, morsal 
surface. (Enlarged.) 



CLASSIFICATION AND DESCRIPTIVE ANATOMY OF THE TEETH. 15 

while the cervico-inarginal line curves slightly downward upon the mesial 
surface only. The greatest difference between these teeth is in the root, 
which is a little longer than the first ; very rarely bifurcated ; is much 
flattened from the cervix to the apex, and often deeply grooved upon the 
mesial surface at the apical third. (See Figs. 38, 39, 40, 41, and 42.) 
Occasionally the root is rounded and conical. Crooked roots are of more 
frequent occurrence than in the other bicuspid, and it has a tendency to be 
rotated in its alveolus, more frequently in a distal than in a mesial direction. 

The pulp-canal is usually single, and gives free access to its apex. 

The average length of the tooth is 0.84 inch (2.13 centimetres). The 
average length of the crown is 0.29 inch (0.73 centimetre), and of the 
root 0.55 inch (1.39 centimetres). 

THE INFERIOR BICUSPIDS. 

These teeth occupy the same relative positions in the lower jaw that the 
superior bicuspids occupy in the upper jaw. They are the smallest of the 
bicuspid teeth, and are distinctive in form, particularly in their morsal 
surface. The transition in form from bicuspids to molars is more marked 
in the lowers than in the uppers. 

In the inferior first bicuspid the lingual cusp is rudimentary, and in the 
second it is large and broad, and divided bucco-lingually through the 
centre by a more or less deep furrow, giving it the appearance of a tri- 
cuspid tooth. 

In architectural form, these teeth are constructed from a single cone, 
the peculiarities of the crown being the result of various additions or 
cingules to the primitive cusp. Unlike the superior bicuspids, the buccal 
and lingual cusps are connected by a transverse ridge. 

The Inferior First Bicuspid. — This tooth is the smallest of all the 
bicuspids, and more nearly resembles a cuspid than a bicuspid, on account 
of the imperfect development or supx>ression of its lingual cusp, which 
is often little more than a cingule. In general outline the crown is much 
more rounded than the superior bicuspids, and its bucco-lingual and 
mesio-distal measurements are nearly equal. 

The buccal surface (Fig. 43) viewed from the buccal aspect, looks like a 
cuspid. In form the buccal surface is a long oval, surmounted by an 
acute point. It is convex in all directions. The buccal cusp is situated 
a little to the distal of the centre of the crown, while the curvature of the 
buccal surface towards the lingual side places the buccal cusp nearly in a 
central position to the long axis of the tooth. 

The Ungual surface (Fig. 44) is convex mesio-dis tally, and nearly straight 
from cervix to morsal margin. The tooth is slightly bent at the cervix 
in a lingual direction, which gives the crown a lingual inclination. The 
length of this surface depends upon the length of the lingual cusp or 
cingule ; usually it is only about half as long as the buccal surface. 

The mesial and distal surfaces (Figs. 45 and 46) are convex bucco- 
lingually, slightly flattened at the cervix, and becoming convex towards 
the morsal margin, which gives a bell shape to the crown when viewed from 
the buccal aspect. 



16 OPERATIVE DENTISTRY. 

The morsdl surface (Fig. 47) is so different from the superior first bicus- 
j)id that a separate description is necessary. In general outline this surface 
approaches a rounded triangle, the width at the buccal, mesial, and distal 
margins being greater than at the lingual margin. It is surmounted by a 
prominent buccal cusp which is located nearly in the centre of the 
surfaee, and a small lingual cusp, though this is sometimes entirely 
absent, and its place occupied by a more or less prominent lingual ridge. 
The buccal cusp has four well-defined ridges descending from it like those 
of the superior first bicuspid. The buccal ridge arises from the summit 
of the cusp and descends to the buccal surface ; the mesial and distal 
morsal ridges usually form a curve with its concavity towards the lingual, 
and are merged into the marginal ridges to form rounded angles ; the tri- 
angular or transverse ridge descends towards the lingual cusp or ridge. 
On either side of this ridge are pits, the mesial and distal pits. The mar- 
ginal ridges are usually well defined. The central groove sometimes 
crosses the transverse ridge ; at other times the ridge is divided by a deep 
sulcus. 

The cervix is very much constricted, and the cervical line but slightly 
curved except at the buccal margin. The enamel at this point sometimes 
forms a prominent ridge. 

The root is single, flattened laterally, long and slender, occasionally 
grooved mesio-distally, is rarely bifurcated, and inclined to be crooked. 

The pulp-canal is small and flattened, and difficult of access. The diffi- 
culties are increased by the lingual inclination of the crown and the ten- 
dency of the root to be crooked. 

The average length of the inferior first bicuspid is 0.84 inch (2.13 cen- 
timetres), of the crown 0.30 inch (0.76 centimetre), and of the root 0.54 
inch (1.37 centimetres). 

The inferior second bicuspid resembles the first so closely in general 
form of both the crown and the root that an especial description, except 
of its morsal surface, would be unnecessary. 

The morsal surface (Fig. 48) of the tooth presents the most marked devia- 
tion in form of any of the bicuspid teeth. It is triangular in outline, like 
the first, but a trifle larger. The buccal cusp is larger and rounded ; the 
lingual cusp not quite so fully developed, and divided bucco-lingually, 
through the centre, by a deep groove, which gives the crown the appear- 
ance of being a tricuspate. The mesio-lingual cusp or tubercle is some- 
times developed at the expense of the disto-lingual, but it is always 
present. Occasionally it appears as a mere cingule on the disto-marginal 
ridge. A well-defined triangular ridge descends from each of the cusps, 
and terminates at the central groove. 

The marginal ridges are well marked. The central groove is generally 
straight, but often curved or angular ; the lingual groove is straight, and 
united with the central groove, forming at the point of union the central 
fossa. The other surfaces are shown in Figs. 49, 50, 51, and 52. 

The average length of the inferior second bicuspid is 0.87 inch (2.20 
centimetres), of the crown 0.31 inch (0.78 centimetre), and of the root 
0.56 inch (1.42 centimetres). 



Buccal cusp 




-Inferior right second bicuspid, buccal 
surface. (Enlarged.) 




lferior right second bieuspii 
surface. (Enlarged. ) 





Fig. 51. — Inferior right second bicuspid, mesial 
surface. (Enlarged.) 



Fig. 52. — Inferior right second bicuspid, distal surface. 
(Enlarged.) 




Lingual 



Lingual 




Buccal groove 
-Superior right first molar, buccal surface. 
(Enlarged.) 



Lingual groove 
Fig. 54. — Superior right first molar, lingual surface. 
(Enlarged.) 




Mesio- 

buccal 

cusp 



Disto-lingual cusp 



Disto-buccal cusp 



-Superior right first molar, mesial surface. 
(Enlarged. ) 



Fig. 56.— Superior right first molar, 
(Enlarged.) 



CLASSIFICATION AND DESCRIPTIVE ANATOMY OF THE TEETH. 17 



THE MOLARS. 

The molars, or tuberoulate teeth, as they are sometimes termed, are very 
different in form and architectural design from those which have been pre- 
viously described. The most simple form of tooth is that designed from 
the single cone. This is the architectural form of the incisors and cuspids. 

The bicuspids are more complex, being formed of two cones. But the 
inferior first bicuspid has but one well-developed cusp and a lingual cin- 
gule. The superior bicuspids have two well-developed cusps, and the 
inferior second bicuspids have three cusps. 

The superior molars are still more complex, being formed by the addition 
o* a third cone to the bicuspid type. This gives the tooth three roots, 
upon which three or four cusps are supported. 

The inferior molars are the most complicated in form of all the teeth, 
being composed of four cones supporting four or five cusps. 

There are twelve molars in man, three upon either side of each jaw, 
above and below. They are situated in the posterior part of the jaws, 
behind the bicuspids, and are designated as the first, second, and third 
molars. The third molar is sometimes termed the dens sapientia, or wis- 
dom-tooth, because of its late eruption. The molars occupy the sixth, 
seventh, and eighth places, respectively, from the median line ; the first 
molar approximating the second bicuspid distally, the second molar ap- 
proximating the first molar distally, and the third molar occupying a 
similar position to the second molar. The function of the molars is to 
crush and triturate the food, and fit it to be acted upon by the gastric juice 
of the stomach. The loss of these teeth, therefore, seriously impairs the 
function of mastication, and inevitably leads to various derangements of 
digestion, and these again to imperfect assimilation and nutrition. The 
preservation of these teeth, therefore, becomes of vital importance to the 
individual. 

The superior first molar is located upon the distal side of the second 
b^uspid. It is the largest and most strongly marked of the superior 
molars, and may therefore be taken as the typical form. It possesses three 
strong roots, and the crown is surmounted by four more or less prominent 
cusps. In general contour the crown is an irregular cpiadrilateral, having 
its angles rounded, two of its sides convex, and two slightly flattened. 
The bucco-lingual diameter is a little greater than the mesio-distal, while 
ie height of the crown is about equal to the mesio-distal diameter. It 
presents for examination five surfaces, — buccal, lingual, mesial, distal, 
and morsal. 

The buccal surface (Fig. 53) is formed by the union of the mesio- and 
disto-buccal developmental lobes, and is divided by the buccal groove into a 
mesial and a distal half, which are quite similar in outline. This surface 

about twice the width of the bicuspids. It is widest at the morsal 
aargin, narrowing towards the cervix, giving a bell shape to the tooth. 
The morsal margin is surmounted by the mesio- and disto-buccal cusps, 
which are separated by a deep notch, through which passes the buccal 
groove to the cervical margin. Sometimes this groove terminates in a pit 



18 OPERATIVE DENTISTRY. 

midway between the morsal and cervical margin. Descending from each 
buccal cusp is a longitudinal ridge, — the buccal ridges, — which are at first 
well defined, but gradually disappear in their course towards the cervix. 

The Ungual surface (Fig. 54), like the buccal surface, is formed by the 
union of the two Ungual developmental lobes, and is divided into a mesial and 
a distal half by the Ungual groove. Both halves are smoothly convex in all 
directions. The morsal margin is surmounted by the mesio- and disto- 
the mesial being the larger. The mesial lobe often carries a 
-a rudimentary fifth cusp. The mesial and distal 
margins converge rapidly towards the cervix, conforming to the palatal 
root. 

The mesial surface (Fig. 55) is nearly flat, except near the morsal margin, 
where it is slightly convex, and at the cervical margin, where it is some- 
times depressed towards the lingual or j)alatal root. The buccal and lingual 
margins are rounded. The morsal margin is concave in the direction of 
the root, while the cervical margin is concave in the direction of the 
morsal surface. 

The distal surface (Fig. 56) is similar to the mesial surface, except that it 
presents a somewhat greater convexity, converging more sharply towards 
the cervix, and more rounded towards the lingual root. 

The morsal surface (Fig. 57) is surmounted by four rounded cusps or 
tubercles designated as the mesio-buccal, the disto-buccal, the mesio-lingual, 
and the disto-lingual cusp ; the latter being, as a rule, smaller than the 
others, and sometimes only arjpearing as a small tubercle. The surface is 
bounded by four marginal ridges of nearly equal length, — the buccal, the 
lingual, the mesial, and the distal, — which unite the bases of the cusps. 

Arising from each cusp and descending towards the centre of the tooth 
is a triangular ridge. The triangular ridges of the mesio-lingual and disto- 
buccal cusps unite to form the prominent oblique ridge. 

On the mesial and distal sides of the oblique ridge are two fossse, the 
central and distal. The bottom of the central fossa is deeply lined by two 
of the developmental grooves, the mesial and buccal grooves. The former 
arises on the mesial surface, crosses the mesio-marginal ridge, and continues 
in an irregular line to the bottom of the fossa ; the latter begins upon the 

and terminates also in the 
iangular groove. A supple- 
mental groove arises from the central pit of this fossa, extending distally 
across the oblique ridge, which is termed the distal groove. It is rarely 
well defined, but occasionally it may divide the oblique ridge. 

The distal fossa is not so large as the central, and is of an entirely differ- 
ent form, partaking more of the outline of the sulcate groove. This fossa 
is traversed by a deep develop mental groove, the disto-lingual groove, which 
arises on the distal margin, follows the line of the fossa, crosses the lingual 
margin, extending on to the lingual surface- to form the lingual groove. 

"When a fifth cusp is present — the mesio-lingual — it is separated from the 
lingual surface by a groove designated as the mesio-lingual groove. Various 
supplemental grooves or wrinkles are found upon the morsal surface of the 
molars, which radiate from these fossse. 




Lingual groove 
Fig. 57. — Superior right first molar, morsal surface. 
(Enlarged.) 



Fig. 58.— Superior right second molar, buccal surface. 
(Enlarged.) 




Disto- 


Mesio- 


buccal 


buccal 


root 


root 



Lingual groove 
-Superior right second molar, lingual surface 
(Enlarged.) 




Fig. 60.— Superior right second m 
(Enlarged.) 



lar, mesial surface. 



P,llrc;il grc>< >ve 



Lingual 





Disto-lingual groove 
Fig. 61.— Superior right second molar, distal surface. Fig. 62.— Superior right second molar, morsal surface. 



(Enlarged.) 



(Enlarged.) 





Buccal groove 
Fig. 63. — Superior right third molar, buccal surfaci 



Lingual cusp 
Fig. 64. — Superior right third molar, lingual surface. 
(Enlarged.) 



CLASSIFICATION AND DESCRIPTIVE ANATOMY OF THE TEETH. 19 

The cervix of this tooth, on section, shows the form of a rounded rhom- 
boid, widest upon its buccal aspect. The cervical line is nearly straight 
upon all four surfaces. A concavity occurs on the buccal side at the bifur- 
cation of the buccal roots, and a slight depression upon the mesial and 
distal sides, with an inclination towards the lingual root. 

The root is divided into three prongs or radicles, two upon the buccal 
side, which are small, tapering, and either flat or rounded, the mesio- 
buccal and disto-buccal, and one upon the lingual side, large, round, and 
tapering, the lingual. The roots are usually separated ; their apices stand 
wide apart. Occasionally, however, they are united for some distance by 
a bridge of cementum ; this most frequently occurs with the buccal roots. 
The mesio-buccal is the largest of the buccal roots. All of the roots may be 
more or less bent and crooked. 

The Pulp- Chamber and Canals. — The pulp-chamber is large and divides 
into three branches, one for each root. The Ungual canal is the largest, and 
is freely entered to its apex, except in those cases in which the root is bent 
or crooked. The mesio-buccal is the next largest canal, and can often be 
entered with ease, but occasionally it is small and narrow, and when the 
root is crooked it often becomes difficult or impossible to follow it. The 
disto-buccal canal is almost always so small and fine as to require great 
skill and much patience to properly cleanse it preparatory to filling. Many 
times the canal cannot be followed to the apex by any degree of skill or 
patience, thus making the proper treatment and filling of these roots one 
of the most difficult problems in the whole range of dental practice. 

The average length of the superior first molar is 0.81 inch (2.05 centi- 
metres), of the crown 0.30 inch (0.76 centimetre), and of the root 0.51 
inch (1.29 centimetres). 

The superior second molar is so nearly the counterpart of the first 
molar that the differences in its form need only be described. It is a little 
smaller than the first molar, not so nearly quadrilateral in form, but 
rhomboidal, being somewhat compressed mesio-distally. 

The buccal surface (Fig. 58) is almost identical with that of the first 
molar. A slight difference is noticed in the mesio-distal width of the sur- 
face and in the location of the buccal groove, which in many instances is 
at the distal third rather than at the mesio-distal centre. 

The lingual surface (Fig. 59) presents a greater convexity mesio-distally, 
and particularly so from the linguo-morsal margin to the cervix. The 
lingual groove is not so constant in its location, often being found between 
the mesio-distal centre and the extreme of the distal third of the surface. 

The mesial and distal surfaces (Figs. 60 and 61) have only slight differ- 
ences. The mesial is inclined to be concaved bucco-lingually ; into this 
concavity the distal surface of the first molar closely fits, while the only 
difference in the distal surface is that it is more markedly convex. 

The Morsal Surface. — The most marked differences in the character of 
the morsal surface (Fig. 62) of the second superior molar is the almost con- 
stant tendency to the suppression of the disto-lingual lobe. This carries 
the oblique ridge farther to the distal side, and enlarges the central fossa. 
The cusps are also not so prominent, and when the disto-lingual cusp is 



20 OPERATlVE dentistry. 

only rudimentary in size, and the oblique ridge prominent, the tooth be- 
comes practically a three-cusped tooth. The various grooves are the same 
as on the first molar in the normally developed organ. 

The cervix is less regular in outline and more constricted and flattened 
mesio-distally than in the first molar. 

The roots are the same in number and general form as in the first molar ; 
they spread less, however, and are quite inclined to be crooked or converge 
towards each other, or to be fused together. 

Sometimes the buccal roots only are fused, while in others the mesial 
and lingual are joined, or all of the roots may be united in a single root, 
the outlines of the roots being marked only by shallow grooves. 

The pulp-canals in a normally developed superior second molar are, as 
a rule, smaller and more difficult to enter than those of the first molar. 

When the roots are fused together, all of the canals may coalesce, 
making a single canal, or when union of the buccal roots takes place these 
canals may unite. The uncertainty, however, as to their regularity in 
form adds greatly to the difficulties to be surmounted in the treatment. 

The average length of the superior second molar is 0. 79 inch (two centi- 
metres), of the crown 0.28 inch (0.71 centimetre), and of the root 0.51 inch 
(1.29 centimetres). 

The superior third molars are smaller than either of the other su- 
perior molars, and show greater deviations from the normal type, being 
very erratic as to the time of their appearance and in their form and struc- 
ture. It is the eighth from the median line, and the last tooth of the upper 
dental arch. This tooth, when well formed, is a tricuspid, the clisto-lingual 
cusp being suppressed. The oblique ridge then becomes the disto-marginal 
ridge. The crown is triangular in form and the angles well rounded. 

The buccal surface (Fig. 63) is like that of the second molar, but more 
rounded and the lobes less strongly marked and the buccal groove shallow. 

The lingual surface (Fig. 64) is usually full and convex in all directions. 
It has but a single lobe on account of the suppression of the disto-lingual 
cusp. 

The Mesial and Distal Surfaces. — The mesial surface resembles the same 
surface of the second molar but is reduced in size, while the distal surface 
is shorter and more rounded (Figs. 65 and 6G). 

The morsal surface (Fig. 67) in a well-developed third molar presents a 
?nesio -buccal, a disto-buccal, and a mesio-lingual cusp, with the suggestion of 
a disto-lingual cusp, in the form of a cingule or tiny tubercle. In this case 
it will also present a central and distal fossa, with the developmental 
grooves more or less distinctly marked. More often, however, the disto- 
lingual cusp is entirely suppressed, and with it the distal fossa. Many 
times the cusps will be so blunted around the central fossa as to give the 
appearance of a continuous marginal ridge, occasionally sharply defined, 
or it may be broadly rounded. 

The cervix is constricted, and in form, on section, gives the outline of a 
rounded triangle. 

The roots have very rarely the form of the typical molar in the higher 
civilized races. As a rule, the roots are fused together to a greater or less 





Mesial groove 
Fig. 65. — Superior right third molar, mesial surfac 
(Enlarged.) 



Distal groove 
-Superior right third molar, distal surface. 



Disto-huccal gr< 





Mesio-lingual cusp 
Fig. 67. — Superior right third molar, morsal surface. 
(Enlarged.) 



Fig. 68. — Inferior right first molar, buccal surface. 
(Enlarged.) 



Mesio-lingual cusp Disto-lingual cusp 



Lingual 





Fig. 69.— Inferior right first molar, lingual surface. Fig. 70.— Inferior right first molar, mesial surface. 

(Enlarged.) (Enlarged.) 



Median- 
Buccal groove buccal cusp Disto-buccal groove 




Mesio- 

buccal 

cusp 

Mesial 
groove 


B..„ 


'- 


jE 


Mesio- 






fi 


cusp 









Disto- 
buccal 
cusp 

Distal 
groove 

Central 



Disto- 
lingual 
cusp 



Fig. 71.— Inferior right first molar, distal surface. 
(Enlarged.) 



Lingual groove 
Ftg. 72. — Inferior right first molar, morsal surface. 
(Enlarged.) 



CLASSIFICATION AND DESCRIPTIVE ANATOMY OF THE TEETH. 21 

extent, sometimes forming a single root, and they are often curved distally 
towards the maxillary tuberosity. Sometimes they have multiple roots, 
which may be curved in various directions. 

The pulp-canals are usually blended into one, but when the roots are 
separate there are individual canals. The difficulties presented in the 
treatment of the root- canals of these teeth are greatly enhanced by the 
positions which they occupy in the jaw and their great liability to have 
crooked roots. 

The average length of the superior third molar is 0.68 inch (1.72 centi- 
metres), of the crown 0.24 inch (0.6 centimetre), and of the root 0.44 inch 
(1.11 centimetres). 

THE INFERIOR MOLARS. 

The inferior molars are three in number, and are designated according 
to their positions in the jaw as the first, the second, and the third. They 
occupy respectively the sixth, seventh, and eighth positions in the inferior 
arch from the median line. 

As already stated, these teeth are constructed upon the architectural de- 
sign of a combination of four cones united at their bases to form the crown, 
while the apices are united in pairs to form the mesial and distal roots. 

The inferior molars differ from the superior in that they have two 
roots instead of three ; are inclined to have multiple cusps ; have a 
greater diameter mesio- distally than bucco-lingually ; and the buccal 
surface slopes towards the centre of the tooth to accommodate the over- 
locking of the cusps of the occluding teeth. 

The inferior first molar is the sixth tooth from the median line, and 
approximates the second bicuspid upon its distal surface. " Next to the 
superior first molar it is the largest tooth in the denture." (Black.) 

The buccal surface (Fig. 68) is an irregular trapezoid in form, the morsal 
margin being wider than the cervical, due to the convergence of the mesial 
and distal surfaces towards the cervix. The surface is convex in all direc- 
tions, and the mesial and distal margins are rounded. The morsal margin 
is usually surmounted by three cusps or tubercles, the mesio-buccal, the me- 
dian-buccal, and the disto-buccal, which are separated by the buccal and disto- 
buccal grooves. The buccal groove is a little to the mesial of the centre of 
the tooth, while the disto-buccal groove is near the disto-buccal angle. 
These grooves generally terminate near the middle of the surface in pits, 
which often become the seat of caries. 

The lingual surface (Fig. 69) is slightly convex in all directions, and in- 
clines towards the lingual. The surface is not so wide as the buccal sur- 
face on account of the convergence of the mesial and distal surfaces towards 
the lingual. The morsal margin forms a rather sharp angle with the mor- 
sal surface ; it is surmounted by two cusps or tubercles, the mesial and dis- 
tal, and is divided through its centre by the lingual groove, which separates 
the mesial and the distal cusps. This groove is shallow and rarely 
extends farther than the middle of the surface. 

The mesial and distal surfaces (Figs. 70 and 71) are flattened bucco-lin- 
gually and convex from morsal margin to cervix, the distal surface more 
than the mesial. They are wider at the morsal margin than at the cervix. 



22 OPERATIVE DENTISTRY. 

The rnesio-inorsal margin is deeply concaved, and the disto-morsal margin 
is notched, sometimes deeply, by the distal groove. 

The morsal surface (Fig. 72) is trapezoidal in form, the buccal side being 
the longest. The surface is surmounted by five cusps, designated as fol- 
lows : the mesio-buccal, the median-buccal, the disto-buccal, the mesio-lingual, 
and the disto-lingual ; three are arranged upon the buccal half of the sur- 
face, and two upon the lingual. The cusps are united at their bases by 
four marginal ridges, the mesio-marginal ridge, joining the mesio-buccal and 
the mesio-lingual cusps ; the bucco-marginal ridge, uniting the mesio-buccal, 
median-buccal, and disto-buccal cusps ; the linguo-marginal ridge, joining 
the mesio-lingual and disto-lingual cusps ; and the disto-marginal ridge, 
uniting the disto-lingual and disto-buccal cusps. These ridges slope 
towards the centre of the teeth to form the central fossa. There are five 
triangidar ridges which descend from the five cusps towards the central 
fossa. The morsal surface is traversed by five developmental grooves, 
the mesial, buccal, disto-buccal, lingual, and distal. 

The mesial groove arises in the central fossa and crosses the mesio-margi- 
nal ridge to the mesial surface ; the buccal groove begins at the central fossa, 
crosses the bucco-marginal ridge between the mesio- and median-buccal 
cusps to the buccal surface ; the disto-buccal groove takes a disto-buccal di- 
rection from the central fossa, dividing the bucco-marginal ridge between 
the median- and disto-buccal cusps ; the lingual groove has its origin in the 
central fossa, crosses the linguo-marginal ridge in a deej) sulcus between the 
mesio- and disto-lingual cusps, and is lost upon the lingual surface. 

The distal groove arises also from the central fossa, crosses the disto- 
marginal ridge dividing the disto-lingual cusp from the disto-buccal. 
Various other pits and supplemental grooves are occasionally observed. 

The cervix on section is rectangular in form, with the sides slightly con- 
caved in the centre, and deepest at the buccal and lingual sides at the begin- 
ning of the bifurcation of the roots. The cervical line is convex upon the 
buccal and lingual sides, and concave upon the mesial and distal. 

The roots are two in number, the mesial and the distal. They are 
long, flattened mesio- distally, and often have a decided distal curvature. 
They are implanted in their alveoli, with their long diameter in a trans- 
verse direction to the jaw. The distal root is larger and more rounded 
than the mesial, the latter having deeper grooves and a greater tendency 
to bifurcation. 

The pulp-canal is formed like the teeth, with two branches. Occa- 
sionally the mesial root will have two canals. The distal canal is the 
largest and quite readily entered, while the mesial canal is inclined to be 
flat or hour-glass-shaped, showing the tendency of this root to bifurcate. 

When separate canals are formed, they are usually very small, and 
often cannot be followed. 

The average length of the inferior first molar is 0.82 inch (2.08 centi- 
metres), of the crown 0.30 inch (0.76 centimetre), and of the root 0.52 
inch (1.32 centimetres). 

The inferior second molar differs from the first in that it has but four 
instead of five cusps, is more quadrangular, rounded, and symmetrical. 



Mesio-buccal cusp groove Mesio-lingual cusp 



Central fossa 



Cervical 




lingual 



Buccal &ro°v< 




gual 



Fig. 73. — Inferior right second molar, buccal surface. Fig. 74. — Inferior right second molar, lingual surface. 

(Enlarged.) (Enlarged.) 



Mesial groove 





Fig. 75. — Inferior right second molar mesial surface. Fig. 7(">. — Inferior right second molar, distal surface. 

(Enlarged.) (Enlarged.) 



Mesial groove 



Median 
Disto-lingual cusp buccal cusp Mesio-buccal cusp 




Central fossa Distal pit 

Fig. 77. — Inferior right second molar, morsal surface. 
(Enlarged.) 



Fig. 78.— Inferior right third molar, buccal surface. 
(Enlarged.) 



Mesio-buccal cusp Disto-lingual cusp 



Mesial groove 



Mesio- 

lingual 

cusp 



'■ ' 



Disto- 

buccal 
cusp 




Fig. 79.— Inferior right third molar, lingual surface 
(Enlarged.) 



Fig. 80. — Inferior right third molar, mesial surface. 
(Enlarged.) 



CLASSIFICATION AND DESCRIPTIVE ANATOMY OF THE TEETH. 23 

The buccal surface (Fig. 73) is convex in all directions, but is divided 
into two lobes by the buccal groove, which is usually shallow. A deep 
buccal pit is often observed in the centre of the surface. The morsal mar- 
gin slopes towards the centre of the tooth as in the first molar, and the 
surface is widest at this point, while the convergence of the mesial and 
distal surfaces makes it narrowest at the cervix. 

The lingual surface (Fig. 74) is similar to that of the first molar, with 
the exception that it is proportionately wider, being nearly as broad as 
the buccal. 

The mesial and distal surfaces (Figs. 75 and 76) are similar to those of 
the first molar, except that the distal surface does not have the distal pro- 
tuberance due to the presence of the fifth cusp ; both surfaces are smoothly 
convex. 

The morsal surface (Fig. 77) is surmounted by four cusps, placed at the 
four corners of the surface. The cusps are rounded and symmetrical, the 
lingual being a little more pointed than the buccal. The marginal ridges 
are well formed and enclose a central fossa. The central fossa is traversed 
by four developmental grooves, all arising from the central pit, which 
cross the four marginal ridges. The triangular ridges are well marked, 
being more prominent than in the first molar. 

The cervix is similar to that of the first molar, but more constricted. 
The cervical line describes about the same irregular curves. 

The roots are about the same as the first molar, except that the diver- 
gence is not so great. There is also a tendency to fusion of the roots. 
Examples of complete fusion are not rare. The roots are usually curved 
distally, or otherwise crooked. 

The pulp-canals are similar to those of the first inferior molar, the distal 
the largest, and the mesial usually much constricted. The same difficulties 
are encountered in opening the canals as are found in the first molars, 
which are augmented by the irregularity in the form of the roots. 

The average length of the inferior second molar is 0.77 inch (1.95 cen- 
timetres), of the crown 0.27 inch (0.68 centimetre), and of the root 0.50 
inch (1.26 centimetres). 

The inferior third molar is similar in many respects to the other lower 
molars. It is the eighth from the median line, and the last tooth in the 
lower dental arch. It approximates the second molar upon its distal sur- 
face. It is x3robably the most erratic in its form of any tooth in the whole 
dental series. There are tivo typical forms, one having four cusps, and sepa- 
rated by four developmental grooves, like the second molar, and the other 
having five cusps andfive developmental grooves like the inferior first molar. 
While these two forms are the most common, there are many variations 
from these types ; the morsal surface is often divided by numerous develop- 
mental grooves, so that six, seven, and even eight well-defined cusps are 
presented. 

The buccal surface (Fig. 78) of this tooth is more convex than either the 
first or second molars, but in all other respects it has the same form. 
When the tooth has four cusps, this surface partakes of the outlines of the 
second molar, being surmounted at its morsal margin by two cusps, divided 



24 OPERATIVE DENTISTRY. 

by the buccal groove. When it has five cusps it is like the buccal surface 
of the first molar, being surmounted at its morsal margin by three cusps, 
which are divided by the buccal and disto-buccal grooves. 

The lingual, mesial, and distal surfaces (Figs. 79, 80, and 81) correspond 
so nearly to the same surfaces of the other lower molars that no separate 
description is necessary, except to notice that the distal surface is more 
convex, and when the fifth cusp is present, often very prominent. 

The morsal surface (Fig. 82) exhibits the greatest variations from the 
other lower molars. 

In the four-cusped tooth, which is the more common form, it is the 
counterpart of the second molar, with the exceptions that the distal cusps 
are rarely so large and well formed as the mesial, and the central fossa is 
sometimes occupied by a central tubercle. 

In the five-cusped tooth, it partakes of the form of the first molar, and 
is frequently larger than the second. The distal cusp is usually placed 
more disto-lingually, the buccal surface is more rounded, and numerous 
supplemental grooves and ridges are often present. 

The morsal surface is sometimes surmounted by six, seven, or eight 
cusps, as many supplemental grooves, and one or more supplemental ridges 
within the central fossa. 

Such teeth are always very large, the grooves deeply fissured, and the 
structure poorly organized, predisposing them to early destruction from 
caries. Occasionally the inferior third molar is much smaller than the 
second, having a circumference of not more than two-thirds as large as 
this tooth. 

A common feature of the crown is its inclination towards a circular 
form. 

The cervix is similar in shape, in the typical forms, to the second molar. 

The roots are, in comparison, smaller and more rounded than in the other 
lower molars. They are generally divided, but have a greater convergence, 
and in some instances are fused together in the form of a single cone, but 
in either case they are almost invariably curved distally, sometimes very 
considerably, so that their extraction is often a difficult operation. Occa- 
sionally the tooth may have three or more roots. 

The pulp-canal is sometimes single, but usually it is divided. The canals 
are, as a rule, difficult to enter on account of the location of the tooth, the 
generally small size of the canals, and the almost certain distal curvature 
of the roots. 

The average length of the inferior third molar is 0.62 inch (1.57 centi- 
metres), of the crown 0.26 inch (0.66 centimetre), and of the root 0.36 inch 
(0.91 centimetre). 

THE DECIDUOUS TEETH. 

The deciduous teeth resemble in every way the same class of teeth in the 
permanent set, with the exception of the first molars. They are, however, 
all much smaller than the permanent teeth, and are much whiter in color. 

The incisors and cuspids of both jaws are similar in form to the teeth 
which succeed them. The cervix, however, is more constricted, and the 
enamel ends more abruptly. The process of resorption of the roots of the 



Disto-lingual cus 




Disto-buccal cusp 



FlG. 81.— Inferior right third molar, distal surface. (Enlarged.) 



Disto-lingual cusj 



])i>tn hueeal cus 




Mesio-lingual cusp 



Mesial groove 



Mesial cusp 



Mesio-buccal cusp 



Median-buccal cusp Buccal groove 

Fig. 82.— Inferior right third molar, morsal surface. (Enlarged.) 



CLASSIFICATION AND DESCRIPTIVE ANATOMY OF THE TEETH. 25 

deciduous teeth, which allows their crowns to fall away, begins in the cen- 
tral incisors at about the fourth year, and is completed at about the seventh. 
In the lateral incisors this process begins at about the fifth year, and is 
completed at about the eighth ; while in the cuspids it is delayed until the 
ninth year, and completed at the twelfth. 

Fig. 83. 




The superior first deciduous molars are unlike the molars of the 
permanent set in that the crown has but three lobes or cusps, mesial, distal, 
and Ungual, which are divided by three developmental grooves, the mesial, 
distal, and buccal. The cusps converge towards the centre of the crown, 
giving the morsal surface the appearance of being smaller than the base of 
the crown. The cervix is constricted, while the enamel ends so abruptly at 
the bucco- cervical margin as to form a prominent ridge, —the buccal ridge. 

Another distinctive feature is that the marginal ridges, triangular 
ridges, and angles are more acute than in the permanent molars. Its 
greatest diameter is bucco-lingually. 

The superior second deciduous molars are larger than the first ; 
the morsal surface is wider, and is surmounted by four cusps, and in other 
ways the prototype of the superior second permanent molar. 

The inferior deciduous molars are similar in general form and out- 
line to the permanent molars. The first molar has four cusps irpon its 
morsal surface, while the second molar, unlike the second permanent 
molar, has five cusps. The cusps and the marginal and triangular ridges 
are more marked and prominent ; the central fossa is large and deep, being 
sometimes divided by the triangular ridges forming two or more fossoe or 
pits. The cervix is constricted and the bucco -marginal ridge prominent. 
The mesio-distal diameter of the crown is greater than the bucco-lingual. 

The roots of the deciduous molars differ from the permanent in that 
they are relatively thinner and longer, and are much more spread or 
divergent to accommodate the crowns of the succeeding bicuspids. 

The pulp-chamber is proportionately much larger than in permanent 
molars, but the root-canals are thin and narrow, making their treatment 
difficult. 

The process of resorption in the roots of the first molars begins at about 
the sixth year, and is completed at the tenth, while for the second molars it 
begins at about the eighth year and is completed at the eleventh. 



CHAPTER II. 

ORIGIN, DEVELOPMENT, AND MORPHOLOGY OF THE TEETH. 

Definition. — Morphology (from the Greek fj.»p<j>7j, form, and X6yo<s 1 a dis- 
course). The science of biologic forms, including their relations, changes, 
and analogies ; the science of the shape and modifications of organs or 
parts considered under the idea of unity of plan. 

Anatomists until quite a recent period have looked upon the teeth as 
members of the osseous framework of the body, but they are now classified 
as portions of the dermal skeleton. This change in the classification was 
brought about by prolonged study and research into their origin and de- 
velopment. 

The invention of the compound microscope has made it possible for the 
scientist to delve into the hidden mysteries of nature and reveal to the 
world the wonders of many of her processes and the secrets of her labora- 
tories ; to picture the wonderfully minute elemental or embryonic cells 
from which organized structures are formed, and the marvellous delicacy 
and precision with which these are arranged in the building of tissues and 
organs. 

The discoveries made by the microscope during the last three or four 
decades in the morphology and the histology of vegetable and animal 
tissues, and in pathology and bacteriology, have been truly wonderful, and 
in no department of science have greater discoveries been made than in 
that department of medicine known as dentistry. 

The researches of Hunter, Bell, and Goodsir marked the beginnings of 
dental morphology and histology, and prepared the way for the later inves- 
tigations into the evolution of the teeth. 

The errors into which these earlier investigators fell were due largely to 
the non-possession of adequate facilities for studying the minute structures 
of the embryonic tissues. With the higher powers of the microscope it 
became possible to delve deeper into the mysteries of the evolution of the 
dental tissues than these old masters had been permitted to do. The re- 
sults of these investigations have proved conclusively that the enamel- 
organs had their origin in the epithelial tissues, and hence were formed 
from the same tissue elements as the hair, the nails, and the epithelial 
lining of the glandular structures of the skin and the mucous membrane, 
— namely, epithelial cells. 

EVOLUTION OF EPITHELIAL TISSUE. 

In order that the student may approach the subject of the evolution of 
the teeth with a clear understanding of the tissue elements which enter 
into their structure, it will be advisable to present in brief review the 
morphology and the character of epithelial tissue in general. 

In all animals which are developed from an ovum (Fig. 84), as soon as 
impregnation has taken place and the proper conditions of incubation are 
26 




Fig. 84. — Graafian follicles, or ova, in various stares of development. X 80. 



-.-v 



Fig. 86.— Transverse section of embryo of chick, eighteen hours incubation, showing epiblast and 
hypoblast. ( After Aby.) 





w 



Fig. 87. — Transverse section of embryo of chick, twenty-four hours incubation. (After Aby.) 




Fig. 88.— Transverse section of embryo of chick, thirty -six hours incubation. (After Aby.) 



Epidermis 




Fig. K9.— Vertical section of human sk 




Fig. 90. — Vertical section of skin of middle finger. X 50. 




Fk;. 91. — Squamous epithelium from buccal cavity. A, squamous epithelial cells; B, salivary corpuscles. 
X 162.5. (V. A. Latham). 




Fig. 9'2. — Longitudinal section of lip of kitten. X 30. 



ORIGIN, DEVELOPMENT, AND MORPHOLOGY OF THE TEETH. 



27 



^—VSr^Z 




Division of mammal ovum (half diagrammatic). 
1, the yolk divided into two globules (cells) with 
nuclei ; 2, quadrupled ; S, a large number of nucle- 
ated cells ; 4, a, b, isolated cells. 



established, — and this is best studied in the egg of the barn fowl, — there 
occurs a rapid proliferation of embryonic cells in the germinal spot or 
disk of Pander. This disk is at 
first composed of a germinal cell, 
which by the process of karyokine- 
sis — indirect division or segmenta- 
tion of the cell — produces a rapid 
multiplication of these elemental 
cells (Fig. 85, 1, 2, 3, 4). 

These embryonic cells soon ar- 
range themselves into two layers, 
known as the epiderm or epiblast, 
and the hypodenn or hypoblast, the 
epiblast forming the upper layer 
and the hypoblast the lower (Fig. 
86). Later a third stratum of cells 
is developed between the epiblast 
and the hypoblast, which is known 
as the mesoderm or mesoblast (Figs. 
87 and 88). 

From these three layers all of 
the tissues and the various organs 

of the body are developed. From the epiblast are developed the various 
layers of the skin (Fig. 89), — viz., the epidermis, or cuticle, the derma, or 
true skin, and the rete mucosum, or Malpighian layer, — the glandular ap- 
pendages of the skin, the hair, the nails, and the entire nervous system. 

From the hypoblast are developed the lining mucous membrane of the 
alimentary tract, of the air-x3assages, of the genital apparatus, the epithe- 
lial linings of the serous cavities, the lining membrane of the heart, the 
blood and lymphatic vessels, and the enamel organs of the teeth. From 
the mesoblast are developed the remaining portions of the body, — viz., the 
bones, muscles, blood-vessels, lymphatic vessels, connective tissue, etc. 

Epithelial cells are common to both the skin and the mucous membrane, 
their peculiar characteristics depending upon their location and their par- 
ticular function, as, for instance, in the skin (Fig. 90) they may form the 
cidicle, or horny layer, when they are squamous or scaly in shape (Fig. 91) ; 
if forming the lining of a tubule of a sweat-gland they are cuboidal ; when 
entering into the formation of the hair-sheath they are columnar (Fig. 92), 
while in the shaft of the hair they become squamous, the cells being over- 
laid like the scales of a fish (Fig. 93). 

In the development of the nail-plate they are also columnar, but rapidly 
become squamous and cornified. 

In the mucous membrane of the mouth the most superficial layer of 
epithelial cells is of the squamous variety, while beneath this lies a layer 
of spinous or furrowed cells, the spines of which interlock with neighboring 
cells, and by this means are held together. Immediately beneath this 
stratum is another, the Malpighian layer, made up of small, soft, roundish 
cells, sometimes oval in form, and arranged in a regular order, standing 



28 



OPERATIVE DENTISTRY. 



upright upon the basement membrane (Figs. 94 and 95). Other peculiar 
epithelial cells found in the mucous membrane of the mouth are known 
as the ciliated columnar cell (Fig. 96) and the goblet-cell (Fig. 97), the 
functions of which with the mucous gland are to secrete mucus. The 
mucous glands are also lined with epithelial cells, usually in a single 
layer, and cuboidal or columnar in form. 

From the deeper strata of epithelial cells, the Malpighian layer of the 




Section of jaw of rab- 
bit embryo, showing 
dental ridge cut across : 
ec, oral epithelium ; e, 
epithelial outgrowth cor- 
responding to future 
enamel organ ; m, meso- 
blastic tissue. 



Fig. 99. 



Fig. 98. formed. 

It is interesting to note the analogy in the mor- 
phology of the teeth and the hair. 

By comparing Figs. 98 and 99, it will be seen that 
the first rudiments of the tooth-follicle and the hair- 
follicle have their origin in the lower layer of epithe- 
lial cells, — Malpighian layer, — which dips down into 
the embryonic tissue of the mesoblast. The likeness 
can be still further traced in the formation of the pa- 
pillae and the invagination of the flask-like bud. (See 
Figs. 100 and 101.) 

Until 1837, when Goodsir published his theory 
of the evolution of the teeth, there had been no dis- 
tinct, formulated teaching upon this subject. This 
theory was at once adopted by anatomists generally, 
and was incorporated into all standard works on anatomy and histology. 

Huxley, Kolliker, Waldeyer, Kollman, and Guillot were the first to 
cast doubt upon the correctness of the theory of Goodsir. In 1860 there 

appeared a treatise by Eobin and Magitot, 
entitled "The Genesis and Development 
of the Dental Follicle to the Eruption of 
the Teeth ;" this proved the Goodsir theory 
to be based upon errors due to methods of 
manipulation. It also contained serious 
errors in the order of the genesis of the 
dental tissues, the most conspicuous of 
which was the statement that the dentin 

First rudiments of a hair from the bulb Was the first part Of the follicle to 
human embryo of sixteen weeks, a, b, jkg formed 
layers of cuticle ; m, m, cells of the rudi- 
mentary hair ; i, hyaline envelope. It was not, however, until the appear- 
ance of the treatise "The Origin and For- 
mation of the Dental Follicle," by Legros and Magitot, that the Goodsir 
theory was fully overthrown. 

The teaching of these authors has stood the test of more than thirty 
years of investigation without a single important statement having been 
successfully controverted. Many facts, however, in relation to the develop- 
ment of the individual dental tissues have since been discovered and be- 
come a part of dental histology. We may, therefore, feel fairly certain 
that in so far as the evolution of the dental follicle is concerned, we are 
resting upon a solid, scientific foundation. 








Yu.. 9M. — Transverse s< 




lis; /■', columnar cells 




Fig. 95.— Columnar epithelial cells. < <>70. 




Fig. 96. — Ciliated columnar epithelial cells. X 670. 



Columnar . '.''"«#; 

epithe^l| 




Goblet- 

;lla 



Fig. 97.— (Goblet-cells. X 500. 



enamel organ 
Dentin papilla* 




Enamel-organ 
before invagi- 



FlG. 100. — Lower jaw of human embryo, ninth to tenth week. X HO. 




Fig. 101.— Verticil 1 section of the sk 



Develop 




^ 



Secondary 
epithelial 
cord 



V ->C£* ...J 

Fig. 103.— Vertical section through head of human foetus, showing completed rudimentary jaws, etc. 



r 



Tongue 



Develop- 
ing tooth 



__ cartilage 
ing hone 



■_ 




Fig. 104.— Lower jaw of human foetus, showing Meckel's cartilage. 80. 



ORIGIN, DEVELOPMENT, AND MORPHOLOGY OF THE TEETH. 



29 



Before proceeding to a study of the accepted theory of the evolution 
of the teeth let us briefly review the theory of Goodsir. 

Goodsir stated that at a very early period of foetal existence a depres- 
sion or groove, which he termed the primitive dental groove, was formed in 
the mucous membrane along the entire circumference of the alveolar border 
of both jaws ; that from the bottom of this groove in each jaw papillae 
arose, ten in number, isolated and uncovered, which represented the future 
deciduous teeth ; that later these papillae became closed in by the approach- 
ing of the walls of the groove and by the formation of separate septa 
between the papillae, thus enclosing each of them in an independent 
follicle. 

The permanent teeth, except the molars, were formed in like manner, 
within what he termed the secondary dental groove, which he located behind 
the primitive dental groove, and formed from the inner or lingual lip of 
the primitive dental groove. In this secondary dental groove were formed 
the ten anterior permanent teeth, — the teeth of replacement, — while the first 
permanent molar was evolved within the posterior portion of the primitive 
dental groove, which had remained open for this purpose ; and the second 
permanent molar is developed from a papilla given off from the first perma- 
nent molar at the seventh or eighth month after birth, and the third molar 
from a papilla given off from the second permanent molar at a still later 
period in childhood. 

A study of the origin and development of the teeth should take into 
account, also, the evolution of the jaws, which may be briefly outlined as 
follows : 

THE EVOLUTION OF THE JAWS. 

In the human subject the first evidence of the formation of the superior 
maxilla is seen very early in the life of the embryo, — viz., at about the 
eighteenth day after conception, by the develop- 
ment of four tiny buds, tubercles, or processes 
near the central portion of that surface of the 
rudimentary head which is destined to form the 
face (Fig. 102), and which are denominated the 
superior or frontal processes or tubercles, and the 
lateral, oblique, or maxillary processes or tubercles. 

The superior processes elongate downward, 
and at the same time approach each other 
towards the median line, where they finally 
coalesce, at about the twenty- fifth day, to form 
the intermaxillary bones and the central por- 
tion of the upper lip. The lateral processes 
likewise elongate, and approach each other 
towards the median line, where they finally, at 
about the twenty-eighth day, meet the superior 
processes, and unite with them, thus forming 
the lateral halves of the rudimentary superior maxillary bone, palate 
bones, the cheeks, the lateral portions of the upper lip, and the velum 
palati (Fig. 103). 




Head of human embryo. (His.) 
i, superior processes; B, B, ob- 



lique 



30 OPERATIVE DENTISTRY. 

Coincidently with the development of the superior maxillae, a simi- 
lar process of development has been going on for the formation of the 
inferior maxilla. At about the eighteenth day two similar tiny buds or 
processes appear just beneath the lateral processes, and grow rapidly to- 
wards the median line, where they unite at about the twenty-eighth day, 
and complete the arch of the lower jaw. Very soon afterwards a little 
cartilaginous band makes its appearance within the central portion of the 
rudimentary jaw, Meckel 1 s cartilage (Fig. 104). This cartilaginous band 
is composed of two parts, which arise from the mallei of the ears, and 
extend forward until they unite at the mental symphysis. Meckel's car- 
tilage gives form and stability to the inferior maxillary arch until ossifica- 
tion takes place, when it disappears by absorption or becomes calcified, 
forming a part of the maxillary bone. 

EVOLUTION OF THE TEETH. 

The earliest evidences of the evolution of the teeth are to be found at 

about the seventh week of intrauterine life, in the shape of a depression or 

involution of the Malpighian stratum of 

the epithelial cells upon the alveolar border 

of the rudimentary jaws (Fig. 105), forming 

what is known as the epithelial band. This 

^i^S^MMW^^ band is composed of the same cell elements 

-^i^i^^$ thai arc found in the epithelial tissue of the 

'^f^Sfl^' e oral mucous membrane, the band or groove 

involution of the Malpighian stra- being bounded by a layer of columnar or 

tum. section of jaw of rabMt embryo, prismatic cells, which include a mass of 

showing thickening of epiblastic epi- „ . ,, 

theiium(e C ) from which the Mai P i g h- polyhedral nucleated cells, the cells m the 
ian stratum (e) begins its growth into centre often being of the denticulated or 

the mesoblast (in) to form the epithe- . . , 

liaiband. (Piersoi.) spinous variety. 

This band or groove, as it descends into 
the embryonic tissue of the jaw, curves slightly inward, and is filled and 
heaj)ed up with flattened epithelial cells, making what is known as the 
dental ridge, the maxillary rampart of Kolliker, Waldeyer, and Kollman. 
The next step in the evolution of the dental follicle occurs between the 
seventh and eighth weeks, when the epithelial band or groove sends off a 
thin lamina or process upon its lingual aspect in each jaw, — the epithelial 
lamina, — which occupies a horizontal position to the epithelial band. Buds 
or processes also appear upon the extremity or edge of the lamina, — the 
primitive epithelial cord, — which elongates and dips down into the embryonic 
tissue of the jaw. At about the eighth week the enamel-organs are clearly 
defined as club-shaped enlargements upon the extremities of the primitive 
epithelial cords (Fig. 106), and the dentin papillce, or dentin bulbs, can be 
discovered as opaque points directly beneath the enamel-organ in the meso- 
blastic tissue. 

Fig. 107 represents the epithelial cord in the preceding illustration, 
highly magnified, and Fig. 108 shows the same in cross-section. 

The process of evolution advances synchronously at this period in all 
the follicles of the deciduous teeth. 




Developing 




Via. 100. — Lower jaw of human embryo, seventh to eighth week. 



Epithelial lami 



Epithelial cord '**£* 




Columnar., 
epithelial cells; 



Polyhedral, or 
flattened,! 

epithelial cells? 



lub-shaped en- 
iixenient of the 
litliciial cord 



Fig. 107.— Vertical section of epithelial cord, or primitive enamel-organ. >; 300. 





Epithelial 
cord 



| >•*./.. 




Fk;. MS — Cross 



>t epithelial cord, X 300. 




Fig. 109. — Primitive epithelial cord, showing a peculiar turning of the end. X 45. 



Dentin 
papillae 



Invagination of enamel-organ 




Invagination of enamel-organ 
Fig. 110.— Vertical section through lower jaw of embryo field mouse. 



Primary epithelial < 



Dentin pa] 




Bud to form the 
secondary epi- 
thelial cord 

Enamel-organ 



Fig. 111. — Evolution of dental follicle at about the ninth week, showing invagination of enamel-organ. 

X 70. 



Odontoblasts 



Kiia!ni'l-<>i'i:;m 



Membrana eboris 



Dentin papilla 



Constriction at 
base of papilla; 




Kxternal epithe- 
"uni of enamel- 
organ 



Membrana elioris 



Internal epithe- 
"um of enamel- 
organ 



Sac of follicle 



Forming Bone 



Fig. 113. — Follicle of human molar at about the eleventh week. X 50. 






ORIGIN, DEVELOPMENT, AND MORPHOLOGY OF THE TEETH. 31 

The club-like enamel-organs now rapidly enlarge and become pear- 
shaped in form. In Fig. 109 a peculiar hook-shaped termination is noticed, 
which is doubtless a malformation, as no reference is made to it by other 
observers, and has not been seen before by the writer. This pear-shaped 
enlargement is due to a rapid proliferation of the polyhedral epithelial 
cells contained within them, and of the columnar cells which form the 
outer boundary. The enamel- organ has now attained its full size, and 
occupies a position within the deeper structures of the jaw, and slightly 
inclined towards its lingual aspect. 

The next important feature in the development of the follicle is the in- 
vagination of the enamel- organs, as shown in Fig. 110. This change occurs 
simultaneously with the appearance and growth of the dentin papillae. 
Immediately beneath each enamel-organ is developed from the mesoblastic 
tissue a cone-shaped bulb or papilla similar to the papillae found in the 
gums and mucous membrane of the mouth. 

The dentin papilla? (Fig. Ill) in its earliest stage of development is com- 
posed simply of embryoplastic neucleated cells, but soon afterwards it con- 
tains fusiform and stellate cells ; it also contains a vascular loop, but Bob in 
and Magitot were unable to discover in it any nerve-fibres. 

As soon as this new organ has assumed a conical form, which occurs at 
about the ninth week, there arises from its base, as seen in microscopic 
sections, two opaque processes, which are the first traces of the wall or sac 
of the future follicle. These processes, which really surround the base of 
the papillae like a collar (Fig. 112), elongate as the bulb increases in size 
and length, converging towards each other until they finally embrace the 
bulb and enamel- organ in their entirety. 

As the dentin bulb enlarges and elongates it comes in contact with the 
inferior portion or lower plane of the enamel-organ, which is gradually 
carried upward until it is completely invaginated, thus forming a double- 
walled cap or hood over the dentin papilla. 

It is interesting to note the fact that during the growth of the dentin 
papilla and the invagination of the enamel-organ a reciprocal adaptation 
of these organs takes place from the commencement of the process, and 
continues throughout all subsequent phases, the enamel-organ at all 
times covering the dentin bulb, and being adapted to its varying con- 
tours (Fig. 113) . At no time, however, during the process of development 
do the tissues of these two organs become united. 

Sudduth confirms the teaching of Legros and Magitot, and says there 
is no union between the enamel-organ and the papilla, nor have vessels or 
nerve-fibres ever been demonstrated as passing from one to the other. 

Bodecker takes an opposite view, and states that when the enamel- 
organ is detached from the dentin papilla, as frequently occurs in making 
sections, there appears upon the outer surface a delicate fringe, which he 
believes to be the true connection between the enamel-organ and the 
papilla. 

Fig. 114 is here introduced to show the stage of general development of 
the human embryo at the eleventh or twelfth week. 

At about the eleventh week a notable change has taken place in the 



32 OPERATIVE DENTISTRY. 

shape of the dentin papillae, which have now assumed the forms of the 
crowns of the teeth which they represent. At this time, also, a narrowing 
or constriction takes place at the base of the papilla, forming a kind of 
neck at the free border of the enamel-organ (Fig. 113). 

In examining vertical sections of the dentin bulb at this period, 
the existence of a thin, clear, transparent zone of amorphous material 
upon the periphery of the organ is discovered. This amorphous material 
is destitute of anatomic elements, somewhat more transparent and denser 
than the subjacent tissue of the dentin papilla, and capable of being de- 
tached from the surface of the latter. This condition led Easchkow and 
others to suppose the papilla to be invested with a distinct membrane, the 
membrana prceformativa of Easchkow, and the membrana eboris of later 
writers. This zone of amorphous material lies between the enamel- organ 
and the dentin papilla (Fig. 115). 

Black, in speaking of this layer, says, " Just before the calcification, 
and even before the odontoblasts make their appearance, the ameloblasts 
and the tissues of the pulp are separated by a well-marked double pellucid 
layer, which in section appears as a double band." Andrews says, "If 
the tissue has been carefully prepared, minute glistening bodies — caleo- 
spherites — are seen under the higher powers of the microscope, in the den- 
tin bulb and within this layer, which indicates the near approach of the 
process of calcification. The first layer of odontoblasts is formed within 
the transparent amorphous material, and although the ameloblasts make 
their appearance first, calcification does not take place in them until after 
the odontoblasts have formed a cap of calcified dentin upon which the 
enamel-rods are to rest (Fig. 116). 

The character of the cells contained within the body of the enamel- 
organ have also become greatly changed, and appear as stellate bodies 
within a reticular structure (Fig. 117). 

The next important change in the process of development is seen at 
about the sixteenth week, iii the form of a tiny but well-defined cap of 
calcified dentin at the tips of the incisors and cuspids, and about a week 
later in the molars (Fig. 118). Calcification has not yet begun in the amel- 
oblasts, although they are fully developed and well defined. The primi- 
tive epithelial cord is still attached to the enamel- organ, and the sac is not 
yet closed. 

Another important change also takes place at this time, — viz., the 
budding of all the primitive cords upon their lingual aspect to furnish the 
enamel-organs for the ten anterior permanent teeth in each jaw. The buds 
rapidly assume a pear-shaped form, as shown in Fig. 119, followed by the 
appearance of the dentin papillae and invagination of the enamel-organs 
shown in Fig. 120. 

Black believes the epithelial cords of the permanent follicles often 
spring directly from the Malpighian layer of the epithelial band (Fig. 121), 
instead of from the primitive epithelial cords, as taught by Legros and 
Magitot. 

At the eighteenth or nineteenth week the sacs of the primitive dental 
follicles are closed, and the follicles separated from their epithelial cords 




Fig. 11-1.— Human embryo at cloven to twelve weeks after conception. 



Stellate 
reticulum 








Amelo- 

blasts 






■\-/?^:r. ■'.' ,•■';" • ' -••■ v'v-^ 


Calco- 

spherites 




'"''^'^-JL^'.'iu , }. : ~~ 




Dentin 
papillae 








Capillary 
blood- 
vessel 




** 






■■ ■'■ V 




' '-■ ■■" ■•...' k ■ i 



Stratum 
interme- 
dium 



First lay- 
ers of 
odonto- 



. Capillary 
jlood- 



Fig. 115.— Vertical section of human molar at junction of enamel-organ with dentin papilla?, showing early stage of 
cell differentiation and zone of amorphous material. (V. A. Latham.) X 300. 



Embryonic connective tissue 
jS9?S' External epithelium of enamel-organ 



stellate reticulum 



Stratum intermedium ' 

Ameloblastoma 
Calcined denting— « 

Dentin papilla*! 
Fig. 116. — Vertical section of 



*ws, 



Forming ameloblasts 
Odontoblasts 

human foetus (partly diagrammatic). 




Fig. 117.— Oblique section of a dental follicle, showing stellate reticulum of the enamel-organ 



Enamel 

Enamel-organ 

Uncalcifled cusp 




™ .Dentin papillae 



Forming bone 



Fig. 118. — Vertical section of human molar, showing early stage of calcification of dentin and enamel. X 



Epithelial cells 



Budding of the 

primitive e " 

thelial cord 




mitive 
epithelial cord 



h,namel-organ 



JJL Dentin papilla 



Fig. 119. — Vertical section of cuspid of human fietus, showing the budding of the primitive epithelial 

cord. X 70. 



Enamel-organ, 
permanent tooth 



Dentin papillae 




Follicle of deciduous tooth 



Fig. 120.— Vertical section of human foetal maxilla, showing the deciduous follicle and pear-shaped enlarge- 
ment and commencing invagination of the enamel-organ of the permanent cuspid. X 70. 




Fig. 121.— Vertical section of incisor tooth, human emb: 




Secondary 
epithelial 



directly fror 
the mucous 



Tongue 



maxilla. (V. A. Latham.) X 50. 



Primary 

epithelial 

cord 

Enamel-or- 
gan, perma- 
nent tooth 
Enamel-or- 
gan, decidu- 
ous tooth 




Fig. 122. — Section of human developing tooth, showing the follicle closed and the primary epithelial cord severed 

from its enamel-organ. 




Fig. 123. — Vertical section of dental follicle of eat, showing the follicle closed. X 9. 



^ 



Enamel-organ 



Capillaries 




Papillae 



Fig. 121. — Vertical section of cuspid, human foetus, showing complete closure of the sac. X 




Forming 
bone 



Meckel's 
cartilage 



Fig. 125. — Vertical section of molar, human foetus, showing deciduous follicle and complete invagination 
of the enamel-organ of the permanent follicle. ■' 70. 



ORIGIN, DEVELOPMENT, AND MORPHOLOGY OF THE TEETH. 33 

(Figs. 122, 123, and 124), then evolution goes on without further connec- 
tion with the parent epithelial layer. 

The follicles of the permanent teeth (Fig. 125) remain attached to the 
cord from which they had their origin, sink deeper into the embryonal 
tissues, and take their places beneath the follicles of the deciduous teeth 
which they are at a later period to replace. 

The permanent molar teeth do not have their origin from the epithelial 
cords of the deciduous teeth. The follicle of the first permanent molar 
has its genesis at the posterior end of the epithelial lamina, beyond the 
origin of the follicle of the second deciduous molar in a bud derived 
directly from the epithelial lamina at about the seventeenth week. The 
follicle of the second permanent molar has its origin in a bud given off 
from the epithelial cord of the first permanent molar at about the second 
or f-'rd month after birth, while the follicle of the third permanent molar 
is ived in the same manner from the epithelial cord of the second per- 
manent molar at about the third year after birth. 

Sudduth believes, as a rule, the epithelial cords of the permanent molars 
arise directly from the Malpighian layer of the oral mucous membrane, 
while Bodecker maintains that all the permanent molar teeth are an off- 
spring of the enamel-organs of the second deciduous molars. 

It is not necessary to follow the various phases of the evolution of the 
fe 1 ^s of the permanent teeth farther, as they are identical with those de- 
ov.jued as occurring in the development of the deciduous teeth. 



CHAPTEB III. 

HISTOLOGY OF THE DENTAL TISSUES. 

Calcification. — In the i3receding chapter the process of development 
of the dental organs was studied to the stage of calcification of the dentin 
and enamel. It was then noticed that although the enamel-organ was the 
first to be formed, and that a layer of specialized columnar epithelial cells, 
the ameloblasts, were arranged in a definite order resting upon the coronal 
surface of the dentinal papilla or dentin germ (Fig. 126), apparently ready 
for the process of calcification ; it is not until later that the deposition of 
lime salts really begins for the formation of the enamel. The formation 
of the dentin begins first by the development of a layer of specialized 
connective-tissue cells, the odontoblasts, covering the dentin germ ; and 
these immediately begin the process of building the first tiny cap of den- 
tin upon each of the lobes or centres of calcification by the deposition of 
lime- salts. 

The odontoblastic cells, which are clearly defined, are somewhat broader 
than the ameloblasts, which are situated immediately above them, and are 
arranged in a single layer. They are at this stage ovoid in form, and are 
apparently embedded in a transparent and structureless gelatinous sub- 
stance, in which small globular masses — calcospherites — are already 
forming. 

The function of the odontoblasts is to superintend the process of calci- 
fication of the dentin by the deposition of calcific material, layer within 
layer, upon the coronal surface of the dentin germ, which by this pro- 
cess constantly decreases in size until the limit of nature is reached. 

The function of the ameloblast is also that of superintending the laying 
down of the lime -salts which are to form almost the entire bulk of this 
tissue. 

Definition. — The term calcification comes from the Latin, calx, lime, 
and fiere, to become, — to become lime ; hence the term is used to express 
the physiologic process by which a deposition of calcium salts, or other 
insoluble crystalline matter, is laid down within an especially prepared 
matrix, as in the formation of bone, cementum, dentin, and enamel ; or a 
pathologic deposition of calcareous materials within tissues where they do 
not normally belong, as in the calcification of the arteries, inorganic 
deposits within serous membranes ; the calcification of tubercular 
deposits, etc. 

By the physiologic process of calcification various tissues are formed 
or built up, — by the aid of especially endowed cells, — like bone, cementum, 
dentin, and enamel. The exact modus operandi by which this process is 
accomplished has not been fully established. 
34 




Fig. 126. — Section of dental follicle, showing- first layers of ameloblasts and odontob 



*' ^ - -„. 






»S5^ 'S^-*?" -5Ss *JS,~ v 

^SH?** ■■■■. «o ^"3^v, ■ sf 










^c 



Flo. 1 -J7. — Section of human femur. six months' l.riu-. show in- i.si.-ohlasts. I"' 1 . 



/ - / 



' feS^ 




Fig. 12S.— Forming dentin, showing odontoblasts. (V. A. Latham.) X 1000. 









&:& 



•''% 



# 



Fig. 129. — Enamel-cells, with nuclei. (R. K. Andrews.) 



HISTOLOGY OF THE DENTAL TISSUES. 35 

That these especially endowed cells, osteoblasts, or bone-builders (Fig. 
127), cementoblasts, or cement-builders, odontoblasts, or dentin-builders (Fig. 
128), and ameloblasts, or enamel-builders (Fig. 129), are the active agents 
in the construction of these tissues is a generally conceded fact. 

The term used to express calcification of the bone is ossification ; in the 
calcification of cementum, cementification ; in the calcification of dentin, 
dentinification ; and in the calcification of enamel, amelification. The process 
in the first three of these is substantially the same. 

There are two methods by which a calcified tissue may be formed, — one 
by the deposition of calcium salts within the substance of a formative 
organ, thus converting it into a calcified structure ; and the other by a 
formative organ excreting from its surface both organic and inorganic 
constituents. The former method is the process by which bone, cementum, 
and dentin are formed ; while the latter is the process by which the shells 
of many niollusks are developed, and by most kistologists thought to be 
the method by which enamel is built up. 

The calcium and other salts necessary for the calcification of these tis- 
sues are held in solution or in minute particles, so small as to be almost 
beyond the reach of demonstration by the highest powers of the micro- 
scope, in the gelatinous or protoplasmic fluid in which these specialized 
cells are embedded. It is from this fluid or semi-fluid medium, the inter- 
cellular substance, charged with these salts, that the cells derive the neces- 
sary pabulum for their nourishment and for the performance of their func- 
tions. The supply of nourishment is derived and maintained by the 
abundant vascular net-work of the neighborhood. 

Eainey discovered, and Professor Harting and Dr. Ord further eluci- 
dated the fact, that the calcium salts in the presence of albuminoid sub- 
stances are changed chemically, uniting with the organic compounds to 
form small globular bodies which were afterwards called calcospherites. 
These bodies are always present in the intercellular substance just before 
and during the process of calcification. 

Eainey found in experimenting with the calcium salts that if calcium 
carbonate be slowly formed in a thick solution of mucilage or albumin, it 
resulted in the formation of tiny globules, laminated in structure, from the 
centre outward ; these globules when in contact coalesced to form single 
laminse in larger masses. 

In the laminated structure of the larger masses, formed by the coales- 
cence of the tiny globules into single laminae one upon another, Eainey 
claimed to find the explanation of the development of shells, bones, and 
teeth. A precipitate of calcium carbonate alone in gelatin was at first mem- 
branous, but rapidly passed into the globular and crystalline forms, while 
a precipitate of calcium phosphate alone became at once crystalline, with- 
out passing through any colloid stage, but a precipitate of the bicarbonates 
and phosphates retained for an indefinite period the colloid form. This is 
interesting from the fact that in calcified tissues like bone, dentin, and 
enamel, the carbonates and phosphates are invariably found associated 
together. 

Professor Harting discovered that the calcospherite is composed of a 



36 OPERATIVE DENTISTRY. 

"profoundly modified albumin," which he termed calcoglobulin, and in 
which the calcium salts are held in some form of chemical combination. 
The calcoglobulin, which is the matrix of the calcospherite 7 is exceedingly 
resistant to the action of acids, alkalies, and boiling water, and is capable 
of maintaining its form and structure even after the greater portion of the 
calcium has been removed. 

Tomes, in commenting upon the character of calcoglobulin, says, " It 
is a very suggestive fact that in the investigation of calcification we con- 
stantly meet with structures remarkable for their indestructibility ; for 
example, if we destroy the dentin by the action of very strong acids or 
by variously contrived processes of decalcification, putrefaction, etc., there 
remains behind a tangled mass of tubes (Fig. 130), the " dentinal sheaths" 
of Neumann, which are really the immediate walls of the dentinal tubes. 

Or if bone be disintegrated by certain methods, there remain behind 
large tubes, found to be the linings of the Haversian canals (Kolliker), 
and small rounded bodies recognizable as isolated lacunae ; and in the cuti- 
cula dentis — Nasmyth's membrane — we have another excellent example of 
this peculiarly indestructible tissue. 

In point of fact, as will be better seen after the development of the 
dental tissue has been more fully described, on the borderland of calcifica- 
tion, between the completed fully calcified tissue and the formative matrix 
as yet not fully impregnated with lime, there very constantly exists a 
stratum of tissue which in its physical and chemical properties very much 
resembles calcoglobulin. 

It would seem, therefore, that the indestructible organic matrix of bone, 
cementum, dentin, and the cuticula dentis was in all probability com- 
posed of this " profoundly modified" albumin, ''calcoglobulin." 

Hoppe-Seyler believes the calcium salt which chiefly enters into the 
hardening process in the calcification of bone, dentin, and enamel, is a 
double salt of carbonate and phosphate, one equivalent of calcium carbo- 
nate combined with three equivalents of calcium phosphate. 

ENAMEL. 

Definition. — Enamel is a vitreous, hyaline substance^ covering the 
entire crown of the tooth in varying thickness, and composed chiefly of 
phosphate and carbonate of calcium. 

Fig. 131. Fig. 132. 





Section of enamel at right angles to the course Three enamel-columns, exhibiting the six- 

of its columns, exhibiting the six-sided character sided prismatic and waving or ovaricose char- 
of the latter ; highly magnified. acter ; highly magnified. 

Histologically, enamel is composed of numerous minute hexagonal 
prisms (Fig. 131), measuring in transverse diameter from 0.0034 to 0.0045 
millimetre and in length from three to five millimetres (Frey), and having 




Fig. 130.— Dentinal sheaths, the residue which remains after decalcification of dentin with strong acids. >( 70. 




Fig. 133— Section o: 



ing human molar. Enamel teased 
X 1000. 



wing ends of enamel-rods. 




... - 



Fig. 134.— .4, transverse section of enamel-rods; B, longitudinal section of enamel-rods: C, odontoblasts, 
showing processes ; D, odontoblasts, foetal kitten ; E, dentin, showing interglobular spaces ; F. dentin, showing 
laminated structure. ( After Stowell . ) 




Fig. 135.— Vertical section of enamel-rods, showing their varicosities. 



PLATE I. 




Showing variroscl uiiamcl-n ids. (After Dr. J. Leon \Y 




Showing rarieosed enamel-rods more highly magnified. (After Dr. J. Leon Williams.) 



PLATE II. 




hly magnified. (After Dr. J. Leon Williams.) 



HISTOLOGY OF THE DENTAL TISSUES. 37 

a common direction at right angles to the surface of the dentin upon which 
they rest. 

These prisms are known as enamel- prisms, enamel-rods, or enamel-col- 
umns. As a rule, the rods are continuous from the dentin to the outer 
surface, and with the exception of numerous varicosities, are the same size 
throughout their entire length ; they are not perfectly straight, however, 
but have a wave-like or spiral course (Fig. 132). At the outer surface, 
and particularly at the angles of the crown, numerous short rods are found, 
which extend only a little distance from the surface, and fill in the inter- 
spaces between the longer rods caused by the increase in the circumfer- 
ence of the outer surface and the turning of the angles. 

A section of enamel viewed from the ends of the rods or prisms has the- 
appearance of a finely tessellated pavement (Fig. 133). The rods are hex- 
agonal in outline (Fig. 134, A), and are separated from each other by an 
interprismatic substance, the nature of which has formed a subject for 
much discussion (Fig. 134, J5). 

The individual enamel-rods appear under the higher powers of the 
microscope to be regularly varicosed, the varicosities not interdigitating as 
formerly taught, but opposite each other, and the interspaces filled with 
the interprismatic substance (Fig. 135). 

Transverse Striations. — With the exception of faint transverse stria- 
tions, the enamel-rods seem to be structureless. Hertz claimed this appear- 
ance was due to intermittent calcification of the enamel-rods. Kolliker 
and Waldeyer believed the striations were due to the varicosities of the 
individual fibres. Bodecker declares that normal, fully developed enamel 
is non-striated, and von Ebner holds the same opinion, and claims that this 
appearance of transverse striations is due to the method of preparing the 
specimens, which are usually mounted in Canada balsam, and as a result 
suffer from a slight acid reaction sufficient to produce the striated appear- 
ance. Sudduth and Febiger hold to the opinion of Kolliker and Waldeyer, 
that the striations are due to the varicosities. Williams also maintains the 
same opinion, and in his recent investigations denies the statements made 
by Hertz, Bodecker, and von Ebner, and claims that while in some specimens 
the varicosities are dimly apparent in some parts, they are decided in others, 
but that they are always present. It has also been stated that each vari- 
cosity represents a calcified ameloblast, but Williams claims that he has 
counted fifteen such varicosities within the length of a single ameloblast, 
and that he has never found less than eight to each cell. The varicosities 
he believes to be due to the globular form of the individual enamel-globules 
which build up the enamel-rods. (See Plates I. and II.) 

Brown Striae of Retzius. — With low powers of the microscope an- 
other and larger form of striation is visible, consisting of brownish lines 
(Fig. 136), the u brown strige of Betzius." They are seen in broad lines, 
nearly or quite parallel with the outer surface of the enamel. 

Tomes suggests that inasmuch as they coincide with what was at one 
time the outer surface of the enamel cusp, they are in some sense marks of 
its stratification in its primary deposit. Williams is of the opinion that 
they are due to a real pigmentation. 



38 OPERATIVE DENTISTRY. 

Lines of Schreger. — Another class of markings upon the surface of 
sections of enamel are known as the u lines of Schreger." These lines are 
invisible by transmitted light ; but with reflected light are plainly seen. 
They are well defined at the point nearest the dentin, but become gradually 
less marked as the outer surface of the enamel is reached ; irregularly 
formed lines extending in a longitudinal direction with the enamel-rods are 
sometimes seen in the enamel near the surface of the dentin. They have 
the appearance of open spaces or cavities, and are sometimes in communi- 
cation with the dentinal tubes. Cracks and fissures are often seen upon 
the surface of the enamel, but these have no special significance except as 
they may be predisposing causes of dental caries. 

Nasmyth's Membrane. — Covering the enamel of young, newly 
erupted teeth is a thin membrane, the cuticula dentis, or Nasmy th' s mem- 
brane. This membrane is thought to be formed from the outer layer or 
tunic of the enamel-organ, and measures in thickness from 0.001 to 0.0013 
millimetre. It is exceedingly resistant to the strongest acids, alkalies, 
boiling, and maceration, but is soon worn from the teeth by the friction of 
mastication. It yields no gluten. (Kolliker). 

Chemic Composition of Enamel. — Enamel is the hardest structure 
of the body, and at the same time, by the arrangement and character of 
its component parts is capable of great resistance to mechanical force and 
the attrition due to the mastication of food. It is almost if not entirely 
destitute of organic matter, and possesses no nutritive canals. 

Von Bibra gives two analyses of enamel, the first from an adult man, 
the second from an adult woman. 

1. 2. 

Man. Woman. 

Calcium phosphate and fluoride 89.82 81.63 

Calcium carbonate 4.37 8.88 

Magnesium phosphate 1.34 2.55 

Other salts : 0.88 0.97 

Cartilage 3.39 5.97 

Fat 0.20 a t race 

100.00 100.00 

Organic matter 3.59 5.97 

Inorganic matter 96.41 94.03 

100.00 100.00 

Williams says, "Enamel is a solid mineral substance, and the finest 
lenses reveal not the slightest difference between enamel ground moist 
from the living tooth and that which has lain in the earth for a hundred 
centuries;" and also, that "mature, completely calcified enamel contains 
no trace of organic matter, therefore no physiologic change is possible in 
completely formed enamel." 

The chemic analyses which have been published from time to time 
have estimated the organic material in the enamel of a human adult tooth 
at from two to seven per cent. The organic material in these analyses was 
estimated simply by loss of weight on ignition. This is evidently the 
source of error, for no account is made of water being a constituent of 
dried enamel. C. Tomes found that after drying elephant's enamel for a 



^ 



\ 



Dentin 

Ik. k».Ai_ 

Fig. 136. — Section of enamel, showing the brown striationa of Retzius. (V. A. Latham.) X 110. 



\ * *M 




Ameloblastic layer 
and ameloblastic 




ate reticulum 



Forming dentin 



Dental i>ai>ill;v 



Fig. 137.— Transverse section of dental follicle, showing first layer of ameloblasts. (V. A. Latham.) X 325. 




Ceased section of developing human molar, showing the ameloblasts. (V. A. Latham.) X 1000. 




Fig. 139. — Developing enamel, showing Tomes's processes at A. (R. R. Andrews.) 



Formed 
amelo- 
blasts 



Forming ameloblasts 



Stellate reticulum 




**: 



■■-:' ■ '3 






■ ■ ■-, -' : -■■..■■ ;,:, 



Pulp 



Fig. 140.— Section of developing human molar, showing the relations of tl 

X 1000. 



structures. (V. A. Latham.) 



Formed dentin 



Odontoblasts 




Pulp 



Fig. 141. — Section of developing human tooth, showing ameloblasts highly magnified. (Zeiss one-twelfth oil 

immersion.) 



I 




Fig. 142. — Section of developing tooth, showing ameloblasts more highly magnified. 



Stratum intermedium 



Formed ameloblasts 



Outer ameloblastic B 



Inner ameloblasti 
membran 






HPH Formed enamel 
ormed dentin 



Odontoblasts 



ulp 



Fig. 143.— Transverse section of developing tooth, showing the arrangement of the tissues. (After 
Andrews.) X 275. 



HISTOLOGY OF THE DENTAL TISSUES. 39 

long time at a temperature of 300° F. that it still contained about four per 
cent, of water. 

In decalcifying sections of fully formed enamel by the aid of acids, it is 
found that the interprismatic substance is first attacked, and the rods fall 
apart, which proves conclusively that the interprismatic substance is a 
calcium cement material, more readily acted upon than the rods them- 
selves. If the process of decalcification is continued, the enamel-rods are 
attacked, and the whole structure is destroyed, leaving behind no evidence 
of an organic matrix. 

CALCIFICATION OF ENAMEL. 

Amelification is the process by which the calcium salts are deposited 
within the matrix constructed by the ameloblasts for the formation of 
enamel. 

As previously stated, the process of calcification first begins in the 
dentin papilla, by the formation of a layer of dentin at those points which 
are denominated the lobes of the morsal edge and the cusps of the morsal 
surface. 

Upon this layer of dentin, which is as yet only partially calcified, the 
first layer of ameloblasts is arranged (Fig. 137). These cells are some- 
what in the form of columnar epithelial cells, have oval nuclei and taper- 
ing processes projecting from their inner ends, — Tomes' s processes (Figs. 
138 and 139). The ameloblasts stand close together, with one end resting 
upon the newly formed dentin, and the other in contact with the stratum 
intermedium, and this again in contact with the stellate reticulum (Fig. 
140). This is further and more beautifully shown in Fig. 141. In this 
illustration the ameloblasts are seen resting upon the formed enamel, while 
the opposite ends are in contact with the stratum intermedium. Fig. 142 
is a higher magnification of the same section. 

Stratum Intermedium. — In the earlier stage of enamel formation, 
various observers have described the presence of what has appeared to be 
a structureless membrane lying between the odontoblasts and the first layer 
of ameloblasts, and another between this layer of ameloblasts and the 
stratum intermedium, the formation and character of which has not been 
demonstrated (Fig. 143). 

Williams has designated these layers by the terms inner and outer 
ameloblastic membrmies, and describes them as being composed of a finely 
fibrous structure. The outer layer or membrane is particularly interesting 
from the fact that it seems to be composed of two sets of fibres running in 
nearly opposite directions, but neither direction corresponding with the 
long axis of the ameloblasts. 

One set of these fibres passes in a somewhat more oblique course than 
the others, and becomes confluent with the ends of the enamel-prisms, 
while the other set sweep downward in a circular course, crossing the more 
oblique-running fibres and the enamel-prisms nearly at right angles. 
Mummery has beautifully shown the interlacing of these fibres. 

Sometimes both sets of fibres join and twist about each other in a 
rope-like design, and pass along the course of the enauiel-prisins. A third 



40 OPERATIVE DEKTISTRY, 

set of fibres may sometimes be seen running parallel to the ends of the 
ameloblasts. These fibres, he thinks, are identical with the plasm-strings 
first discovered by Andrews, which are often visible in the ameloblasts. 

With a magnifying power of from one thousand to two thousand three 
hundred diameters, he discovered the inner and outer ameloblastic mem- 
branes to be composed of several layers of protoplasmic strings or fibres. 
These processes or strings are often seen to emerge from the inner ends of 
the ameloblasts, and turn to the right and left. He thinks it quite possible 
that the structures, which he has designated as the inner and outer amelo- 
blastic membranes, are formed by the accumulation of the calcific albuminous 
product of the stratum intermedium within the meshes of these plasni- 
strings, which spread out on both ends of the ameloblasts, forming a struc- 
ture resembling a membrane (Fig. 144.) 

Blood-Supply of the Enamel-Organ. — Wedl, Magitot, Tomes, Sud- 
duth, Andrews, and others have stated that they have uniformly failed to 
detect blood-vessels in any part of the enamel-organ. A reference to Fig. 
145 will show the enamel-organ to be abundantly supplied with blood- 
vessels, which cover its entire outer surface. But Williams has shown 
conclusively in recent papers published in the Dental Cosmos for 1896 and 
1897, accompanied by numerous most excellent photo- micrographs, that 
not only are blood-vessels seen within the enamel-organ, but that they 
are found within the stratum intermedium in an intricate plexus. The 
ameloblasts are surmounted by epithelial papillae, which Williams terms 
11 secreting papillae" (Figs. 146 and 147), and these are surrounded by a 
free distribution of capillary loops. The ameloblasts seem to be con- 
nected with the papillae by root-like processes, which are lost in the sub- 
stance of the papilla to which they belong. 

The papillae (Figs. 148 and 149) are from five to six times as large as 
the ameloblasts, and may therefore supply from twenty to twenty-five 
ameloblasts. These he believes to be secreting organs. 

He further states that, although the stratum intermedium in forming 
human enamel is not very striking in its resemblance to glandular tissue, 
aside from the arrangement of its blood-vessels, that nevertheless in 
studies of the evolution of the enamel- organ of the mouse and rat its place 
among glandular structures at once becomes evident. He also states as 
his opinion that the function of the stratum intermedium is undoubtedly 
to select from the blood brought to it by its capillary vessels the necessary 
material for the construction of the enamel. He explains the difficulty in 
the theory of the formation of enamel before the development of the 
stratum intermedium, by suggesting that the material necessary for the com- 
mencement of enamel formation is stored up in the stellate reticulum of the enamel- 
organ. 

Charles Tomes does not agree with Williams in his conclusions in refer- 
ence to the presence of blood-vessels in the stratum intermedium or in the 
supposed secreting function of the papillae of the stratum intermedium. 

Spee and Andrews have taught that the process of calcification of the 
enamel was due to the deposition of "droplets" or spherules of cal co- 
globulin formed within the ameloblastic cells, and excreted or shed out 



Stellate reticulum , 



Masses of 
calcoglobulin 
in calcifying 

ameloblasts 




Stellate reticulum 



Outer ameloblastic 
membrane 



Inner ameloblastic 
membrane 



Stratum intermedium 
Calcifying enamel 



Dentin 
IP 



Fig. 144.— Developing tooth of embryo lamb. (After Andrews.) X 105. 





Blood-vessel, 

arising from 

base of dental 

papilla 



Fig. 145.— Vertical section of central incisor of human foetus (injected), showing blood-supply of enamel- 
organ. (V. A. Latham.) 



Papillary layer, 

ameloblasts lying 

beneath 




Formed dentin 



Formed enamel 



Fig. 146. — Transverse section of dental follicle of rat, showing papillary layer. (V. A. Latham.) X 



Capillary blood- 




Fig. 147. — Section of forming enamel from jaw of rat, showing enamel papillae, blood-vessels, and fibrillse. 
(V. A. Latham.) X 325. 




Fig. 148.— Section of incisor of a rat. (J. Leon Williams.) X SO. A, capillary loops torn out of secreting 
papillae ; B, secreting papillae after removal of capillary loops ; C, ameloblasts ; D, enamel ; E, dentin. 



Spherules of calcoglobulin 




Fig. 149.— Ground section of developing tooth of rat, showing secreting papillae of Williams. (Von Koch 
method.) (V. A. Latham.) X 97. 







;y- 




a 



' V 'i>*C'~-l 



Fig. 150.— Forming enamel. (R. R. Andrews.) .4, globular bodies of calcoglobulin forming enamel-rods. 



r 








• 






f. 



L 



JL 



Fig. 151.— Section of forming enf 



salcospherites forming the 



HISTOLOGY OF THE DENTAL TISSUES. 41 

(Kolliker) by them at the extremities nearest to the odontoblastic layer to 
form or build up the individual enamel-rods, the fibres of Andrews, acting 
as a sort of reticulum or scaffolding to determine their arrangement. 

Williams states that the "albumin-like substance secreted from the 
blood-vessels by the cells of the stratum intermedium" is absorbed by the 
ameloblasts and deposited by them in globular masses, which he terms 
" enamel-globules," to form the enamel-rods (Fig. 150). 

He thinks these l ' globular masses of spongioplasm' ' are successively 
formed within the ameloblasts themselves. "The cytoplasm of the amel- 
oblasts has a fairly uniform structure, which consists of a number of 
globular masses of spongioplasm of the same diameter as the cell, and 
united longitudinally by somewhat coarser plasm-strings, the fibres of 
Andrews. 

He says further, "there are many indications that these 'enamel-glob- 
ules' are formed by the nucleus of the ameloblast, and they appear to pass 
down the cell by the natural process of growth as new ones are formed 
above, to be finally shed off the inner ends of the cells onto the surface of 
the forming enamel, where they become completely infiltrated with the 
albumin-like lime-conveying substance and calcified" (Fig. 151). 

The " enamel-globules, " which are uniform in size (Fig. 152), are, 
according to Williams, quite distinct from the more transparent and 
irregularly sized masses of calcoglobulin, and that the enamel-rods are 
built up by the successive, rhythmical, orderly deposit of these "enamel- 
globules," while the larger and more irregular-sized bodies of calcoglobulin 
melt and flow together to form the interprismatic substance. 

The elder and younger Tomes both held the theory that the cell- wall of 
the ameloblasts may be calcined to form the interprismatic substance, 
while the cell-contents solidify into the enamel-rods proper. 

Heitzmann and Bodecker promulgated the theory that the interpris- 
matic substance was composed of a reticulum of living matter, and that 
enamel formation was due to the breaking up of the ameloblasts into "em- 
bryonal corpuscles, " which afterwards become calcified to form the enamel- 
rods. This theory for a time dominated the minds of a very large propor- 
tion of American dentists, influencing their practice accordingly. 

This view taught that physiologic changes took place from time to 
time in the structure of the enamel through its reticulum of living matter. 
Later investigations have demonstrated the fact that these authors were 
mistaken in their conclusions, and as a result the theory has to-day few 
advocates. 

DENTIN. 

The dentin is an organic calcified tissue, non-vascular, less dense than 
enamel, and harder than bone, which it somewhat resembles. It forms 
the central portion and greater bulk of the hard structures of a tooth, com- 
pletely investing the pulp from which it is generated ; it is covered and 
protected at the crown by a layer of enamel, while the root is encased with 
a layer of cementum (Figs. 153 and 154.) If the enamel and cementum 
should be removed, the dentin would still retain the general form and 
characteristic features of the tooth. 



42 OPERATIVE DENTISTRY. 

The dentin is a dense, highly elastic substance, white or yellowish- 
white in color, and to some extent translucent. 

Vascular canals are occasionally seen in human dentin, but they are 
to be considered as abnormal conditions. 

The dentin consists of an organic matrix strongly impregnated with the 
calcium salts. 

The Matrix. — The matrix of fully formed dentin appears to be struc- 
tureless, although there are instances in which there are indications that 
at some time during the development of the dentin connective-tissue fibres 
were present (Mummery). 

The proportions of the organic and inorganic constituents are so varia- 
ble that no cheniic analysis could be considered other than approxi- 
mating the exact amounts in even the same individual, as the relative 
quantities are constantly changing from childhood to old age. The rela- 
tive proportions are also very variable in different individuals. 

Von Bibra gives the following analysis of perfectly dried dentin, the 
first an adult man and the second a woman twenty-five years old : 

1. 2. 

Man. Woman. 

Organic matter (tooth cartilage) 27.61 20.42 

Fat 0.40 0.58 

Phosphate and fluoride of calcium 66.72 67.54 

Carbonate of calcium. 3.36 7.97 

Phosphate of magnesium 1.08 2.49 

Other salts 0.83 1.00 

100.00 100.00 

Galippe gives the relative proportions of organic and inorganic matter 
in dentin as follows : 

Water and organic matter 25.29 

Mineral matter 74. 71 

100.00 
Mineral Matter. 

Soluble ash (alkaline chlorides and phosphates) 0.54 

Calcium carbonate 0.35 

Magnesium carbonate 1.13 

Calcium 45. 11 

Magnesium 1.67 

Phosphoric acid 23. 70 

Silicates 0.04 

Undetermined 1.30 

Black, in his experiments upon the "Physical Characters of the Human 
Teeth," Dental Cosmos, 1895, found the analysis of the dentin of two hun- 
dred and sixty-eight teeth taken from one hundred and eleven different 
persons to give the following results : 

Average age of the individuals from whom the teeth were taken 

was, in years 32.33 

Specific gravity of the dentin 20.92 

Percentage of water 11.06 

Percentage of lime salts 63.54 

Percentage of organic matter 25.36 




Fig. 152.— Section of forming enamel, calcoglobulin spherites being deposited to form the enamel-rods, 

(R. R. Andrews.) 



Knamel 


„._ _ ... 


L ' ■ 




■> 


m 




^ 


^31 


Dentin 


' wt 1 




Pulp-cavity 


p'-- 




Cementum 




IP ■ ] 




Fig. 153— Longitudinal section of an 
incisor. (After Stowell.) 



Fig. 154. — Longitudinal section of an inferior 
molar. (After Stowell.) 



Pulp-canal 




Dentinal tubuli 



Secondar}- dentin 



Fig. 155.— Transverse section of root of human bicuspid, showing radiation of the dentinal tubuli. 




Fig. 156.— Normal dentin at dento-enamel junction, s! 



ing dentinal tubuli. (F. B. Noyes.) X 



HISTOLOGY OF THE DENTAL TISSUES. 



43 



The Dentinal Tubuli. — The matrix is everywhere permeated by a 
system of parallel canaliculi or tubuli, the dentinal tubuli, which radiate 
from the pulp-cavity towards the outer surface of the deutiu (Fig. 155). 
The diameter of the tubuli is from 0.0011 to 0.0023 millimetre and up- 
ward (Frey). (Plate III.) 

The dentinal tubules are similar to the canaliculi of bone in that they 
are provided with a special lining layer or sheath, the dentinal sheath of 
Neumann. 

In following the course of the dentinal tubuli, if will be noticed that 
they do not form a straight line in their passage from the pulp-canal to the 
surface of the dentin, but that they describe two, more often three, undu- 
lating curves, and within these many very small, more or less angular or 
spiral bends, of which about two hundred may be counted in the length 
of a line (Fig. 156). (Eetzius.) 

It is further observed that like the canaliculi of bone the dentinal tubuli 
give off numerous branches in their course which unite with neighboring 
tubuli and with each other (Fig. 157). As the tubuli approach the sur- 

Fig. 157. 




Section of root, parallel to dentinal canals. (After Stowell.) 

face the division is more rapid, and the size of the branches is correspond- 
ingly decreased. At the external surface of the dentin many of the 
tubules unite by anastomosis (Fig. 158), others terminate in the granular 
layer of Purkinje and Tomes, while a third set penetrates the cementum 
and may unite with its lacunae through their canaliculi ; or enter the 
enamel by means of the open spaces, or interstices between the enaniel- 



Fig. 158. 




1, tubuli of dentin ; 



rods, already referred to as existing in that portion of the enamel next to 
the dentin (Fig. 159). This system of canals terminates, or rather has its 
beginning, in free openings upon the internal surface of the pulp-canal. 



44 OPERATIVE DENTISTRY. 

Fig. 160, which, is highly magnified, shows the dentinal fibrillse crossing 
from the dentin to the enamel and apparently passing between the enamel 
rods. 

The Dentinal Sheaths. — The dentinal sheaths, or walls of the tubuli, 
as they are termed, are composed of a singularly indestructible substance, 
which is peculiarly resistant to the action of acids, boiling in caustic alka- 
lies, or to putrefaction ; caries does not destroy them, and they can also be 
demonstrated in fossil teeth; this substance is in all probability "cal co- 
globulin." 

Neumann and Henle are of the opinion that the dentinal sheaths are 
calcified. The existence of the dentinal sheaths can be demonstrated by 
decalifying the dentin with strong acids. This process requires several 
days for its accomplishment. The residue is found to be composed of a 
tangled mass of a fibrous-appearing material (Fig. 161) which upon care- 
ful examination is found to be composed of the dentinal sheaths. 

Magitot and Sudduth are of the opinion that the dentinal sheaths do 
not exist as structures distinct from the fibrils. 

Bose demonstrated the presence of the sheaths of Neumann by Golgi's 
rapid method of staining with nitrate of silver. If the tooth is previously 
prepared by Weil's method, the soft parts, including the dentinal fibrils, 
do not take the stain, so that in transverse section the fibril is seen as a 
bright point in the centre of the black dentinal sheath. (Plate III.) 

Tomes is inclined to the belief that the dentinal tubuli possess definite 
lining walls ; but yet suggests that it is possible that their seeming exist- 
ence may be the result of the action of the agents used in the preparation 
of the specimen. He also calls attention to the fact that that part of the 
matrix immediately embracing the fibrils differs in chemic constituents 
from that which makes up the bulk of the matrix. 

Dentinal Fibrils. — The dentinal tubules (Plate IV.) are occupied for 
their entire length by solid fibriilse or processes given off from the odonto- 
blasts, which are known as Tomes' s fibrils, or the dentinal fibrils, the function 
of which, it is supposed, is to transmit sensation and possibly nutritive 
fluid from the plasma of the blood. These questions, however, have never 
been satisfactorily settled. The fibrils of Tomes are solid structures which 
fill the lumina of the dentinal sheaths, so that it would seem impossible for 
them to carry fluid except by a process of osmosis. Histologists have not 
been able to determine the real nature of the fibrils, though there is no 
doubt from the clinical stand-point that they carry sensation. 

Some writers have asserted that the terminal nerve-fibres of the pulp 
pass between the odontoblasts, and either unite with the dentinal fibrils 
or accompany them into the dentinal tubuli. Others are of the opinion 
that the non-medullated fibres of the pulp become united with the stellate 
layers of cells which lie beneath and are connected with the odontoblasts, 
and that thus the power of carrying sensitive impressions is conveyed to 
the dentinal fibrils ; while still others have thought that the sensitiveness 
of the dentin was due to the transmission of vibrations to the pulp, through 
a fluid contained in the tubules, or some other inert conductor. 

Boll (1868) was the first investigator to make authentic observations in 



PLATE III. 

r 7 ' ; ^ : * € ~ ** " '&' # r 

?*■ « * m •% , t» |# 
* * * •» *-«*•«•• * # 

" " ,, tt ft * « • # f • 

C ft * * 4 ****** # 

r * V • * * • •*« . 

- >. " a '• • • * * • * 

1 & ' ft « 

v *'! a * a * n a 11 # I 

' o N * * I 

v ^ a A * A m # ### 

"■ •■■ ""•■„* >:••' 

l r *;** * * • f #* • ' 

t ■ n ,*\ M . ft ■ . ^% ** ■ # :.- ft A J 
I „ n *% A N - # -# • # */ 

Normal dentin showing tubuli in crows section. (F. B. Noyes.) Highly magnified. 



PLATE IV. 




Normal dentin showing tubuli in longitudinal section. (F. B. Noyes.) Highly magnified. 



Dentinal tubuli IM 
entering th< 
ename 





Caries 
following 



-m^ 



Fig. 159. — Section of dentin and enamel, showing tubuli entering the enamel. (V. A. Latham.) 

Ameloblasts Formed enamel 




Fig. 160. — Vertical section of developing human tooth, showing dentinal fibres passing from the dentin to the 

enamel. X 1000. 




Fig. 161.— Dentinal sheaths isolated by decalcification of the dentin. >< 273. 




■ Enamel 



Interglobular .- , 
spaces ^ 



s& 



Interglobular 







Fig. 162. — Vertical section of enamel and dentin, showing interglobular spaces. X 50. 



HISTOLOGY OF THE DENTAL TISSUES. 45 

the endings of the nerves of the pulp. His observations were made upon 
the pulps of the canine teeth of young rabbits and guinea-pigs, some of 
which were stained with gold chloride ; others were fixed for a short time 
in dilute chromic acid solution, teased out and mounted in this solution. 
With the gold-chloride method the results were negative. The chromic 
acid method enabled him to make out numerous medullated and non- 
medullated nerve-fibres in the tooth-pulp. Lying beneath the odonto- 
blastic layer was an especially dense net-work of non-medullated nerve- 
fibres. From this net- work he discovered fine fibrillse passing between the 
odontoblasts, some of which could be traced for a considerable distance 
beyond. He did not, however, succeed in tracing these fibrillar into the 
dentinal tubules, but he felt sure, although unable to demonstrate it, that 
they did enter the tubules, and he assumes there are two kinds of tubules 
in the dentin, those which carry the dentinal fibrils and those which carry 
the nerve-fibrils. 

Underwood and Mummery have demonstrated by the gold-chloride 
method the presence of nerve-fibres arising from the deeper portions of 
the pulp which run directly to the dentin, and appeared as though they 
entered it, thus far confirming the observations of Boll. 

Tomes says, the dentinal "fibrils are not nerves in the ordinary sense, 
and were never supposed to be ; but there are many examples of cellular 
structures which are connected with the termination of sensory nerve-fibres, 
such as the goblet-cells in the olfactory membrane of the frog, and it is 
quite possible that the odontoblasts may stand in some such relation to the 
nerves of the pulp, the terminations of which have even not yet been 
satisfactorily traced." 

Mummery found later that by following Boll's method of preparation, 
by Weil's process, and also by decalcification processes, that he could trace 
a great number of fibres which pass from the pulp to the dentin, these 
fibres being much smaller than the dentinal fibrillse. 

He was not, however, able to see what became of them after they 
reached the dentin. By means of various stains, especially iron, followed 
by tannin, he was able to show them stained, and they appear to be trace- 
able backward into nerve-trunks a little below the surface ; these trunks 
consisted of bundles of non-medullated nerve-fibres, in fact, axis-cylinders. 
He believes the dentin is permeated by dentinal fibres and also by much 
finer fibres, some of which run up towards it from fusiform cells which 
lie near the surface of the pulp, while others appear to come from points 
deeper down in the pulp, and to be devoid of fusiform enlargements. 

Charters White is of the opinion that these fibres, after they leave the 
bases of the germinal corpuscles, enter the fibrous tissue of the pulp and 
become fused in the outer coat of the nerve, but that as yet these facts 
have not been positively demonstrated. 

Coleman compares the odontoblasts to tactile corpuscles, Pacinian 
bodies, the rods and cones of the retina, and the termination of the audi- 
tory nerves in the cochlea. He believes that a connection exists between 
the odontoblasts and the nerve-fibres, but does not consider it as absolutely 
necessary to make out such a connection between the nerve-fibres and the 



46 OPERATIVE DENTISTRY. 

sensitive part. He says, " The impression received by the long processes 
of the odontoblasts might be conducted from these bodies through numer- 
ous cells which intervene between them and the nerve-fibres, or possibly 
the connective tissue of the pulp may perform this office." 

Magitot speaks very positively of the terminal fibrils of the nerves of 
the pulp being continuous with a layer of reticulate cells, which lie imme- 
diately beneath the odontoblasts, and that these communicate freely with 
the processes of the odontoblasts, so that there is a very direct communica- 
tion between the nerves of the pulp and the dentinal fibrils. 

Sudduth has never been able to demonstrate any connection between 
the terminal nerve-fibres of the pulp and the odontoblasts. 

Klein maintains that the only function of the odontoblasts is to form 
the dentin matrix, and that the dentinal fibrils are long processes given 
off from the deeper cells of the dentinal papilla, and that they run up 
between the odontoblasts and enter the dentinal canaliculi. 

Eobertson found, in examining sections of the tooth-pulp of the ox 
which were prepared by fixing and teasing in osmic acid, that the axis- 
cylinders of the medullated nerve-fibres lose their medullary sheaths, and 
after extending for a greater or less distance, become continuous with the 
pulp processes of the odontoblasts, which, therefore, with their dentinal 
processes may be considered as nerve-end organs. 

Bodecker says, " In specimens of nine-month foetal pulps, sufficiently 
stained with gold chloride, I have observed that the medullated nerve- 
fibres upon approaching the periphery of the pulp are destitute of their 
myelin sheath, and now become bare axis-cylinders, split up into numer- 
ous extremely delicate beaded fibrillar, the axis-fibrillae." 

Deutz made sections from embryos in which about one-half of the 
dentin was formed, and discovered pear-shaped bodies arranged with great 
regularity a short distance within the border of the dentin, the small 
ends being directed towards the pulp and connected by the small ends 
with one or more dentinal tubes. Each of these pear-shaped bodies had 
two or three nuclei, and upon the whole quite closely resemble certain 
forms of nerve-end organs. 

Retzius demonstrated (1895), by the aid of Golgi's method of staining 
sections from the teeth of rats, that the nerves of the pulp resolve them- 
selves into fine varicosed fibrils, which extend through a layer of odonto- 
blasts as far as the dentin, but did not penetrate into the latter. 

Huber found by the use of the intravenous methylene-blue method of 
Ehrlich, — injection of a methylene-blue normal salt solution into the ves- 
sels of a narcotized animal which produces a stain of the peripheral 
nerves, — in which a one per cent, of methylene-blue normal salt solution 
was used, was injected into the carotid artery of a rabbit immediately 
after killing it with chloroform. Thirty minutes later the jaw was 
removed, broken open, and the teeth removed, care being taken not to 
injure the pulps. The pulps were then removed and placed at once upon 
a slide moistened with a normal salt solution. 

Such freshly prepared specimens showed the axis- cylinders of the pulp- 
nerves stained with the characteristic blue color, the other tissues not at 



HISTOLOGY OF THE DENTAL TISSUES. 47 

all or only faintly blue. Such specimens must be fixed at once, as the 
color will otherwise fade very quickly. As fixatives, Huber used a satu- 
rated solution of ammonium picrate, or a solution of ammonium molyb- 
date. The former was mounted in a mixture of glycerol and the ammo- 
nium picrate solution, the latter dehydrated and mounted in balsam. By 
these methods the tissues of the pulp become very clear. 

In examining the terminal branches of the medullated nerve-fibres of the 
tooth-pulp, he found that on approaching the surface of the pulp they lose 
their medullary sheath, and the non-medullated terminal branches, after 
repeated division, form a plexus immediately beneath the odontoblasts. 

The non-medullated terminal branches are often beset with nuclei -, 
they branch and rebranch into long, delicate varicose fibres which may 
often be followed for long distances. 

This accords with the observations of Retzius with the Golgi method. 
Huber found as did Retzius, "that terminal fibrils given off from the 
plexus of a varicose fibre found under the odontoblasts pass up between 
the cells, to terminate usually in fine granules near the free end of the odonto- 
blasts. Now and then some small fibril may be traced as it takes a tangen- 
tial course over the free ends of the odontoblasts, as was found by Retzius." 

These observations, he thinks, taken with those of Retzius, "warrant 
the statement that the terminal branches of the pulp-nerves end between 
the odontoblasts near their free surface, occasionally between these cells 
and the dentin, and that they do not make any connection with the odonto- 
blasts nor with any of the cellular elements of the pulp." 

He was never able to trace any nerve-fibril beyond the odontoblastic 
layer. 

Interglobular Spaces. — The " interglobular spaces of Czermack" are 
a system of irregular cavities of extreme variableness in size, which exist 
normally in the dentin, and are the interstices or spaces between the 
rounded projections of numerous spheroidal or rounded bodies or masses 
grouped together within the basis substance of this tissue, and designated 
as dentin globules (Figs. 162 and 163). They are found principally at the 
union of the dentin with the cementum, where they are small and very 
numerous, forming what is generally known as the "granular layer of 
Tomes" (Fig. 164). 

Many of the dentinal tubuli have their endings in these spaces. The 
granular layer is also found in that portion of the dentin which lies be- 
neath the enamel, but in this location it is not so strongly marked. 
Although the interglobular spaces are most numerous at the periphery of 
the dentin, they are not confined to this location, but may be found in all 
parts of this tissue. These spaces, which in dried sections of dentin 
appear as open spaces, with irregular outlines and sharp-pointed x>rocesses, 
extending in all directions, giving them the appearance of lacuna?, are 
in the fresh state filled with calcoglobulin which has not become fully 
calcified. 

Broomell claims they are filled with a soft living plasma, having a 
structural arrangement similar to the basis substance or matrix of the. 
dentin. 



48 OPERATIVE DENTISTRY. 

Tomes is inclined to tLe opinion that the larger interglobular spaces 
found in the deeper portions of the dentin ought not to be considered as 
a normal condition, but rather as an indication of an arrested development. 

The dentinal tubuli are not arrested by the interglobular spaces, but 
pass through them without interruption in their course. 

Bodecker claims that the spaces of the granular layer are filled with 
living plasma, and that through this the soft fibrils within the tubuli are 
in communication with the soft contents of the lacunae and the canaliculi 
of the cementum. 

Incremental Lines. — Certain lines are to.be seen, particularly in the 
crown of the tooth, indicating the laminated structure of the dentin ; 
these have been called the "contour lines of Owen" and the "incremental 
lines of Salter" (Fig. 165). They find their explanation in the laminar 
growth of the dentin, as already indicated. 

Development of the Root.— The root of the tooth is formed as a 
result of the progressive lengthening of the pulp (Fig. 166 and Fig. 167) 
and the continued production of Tomes' s fibres, of the canaliculi and the 
ground substance or matrix, through the agency of the odontoblasts or 
other formative cells. The process is the same as that already described 
in the development of the crown, — viz., the formation of cup-like layers or 
laminae one within the other. 

If a forming tooth is examined at that stage in which the crown has 
been completed, a deep cup-shaped depression will be noticed over the 
whole radial end of the crown, this being occupied by the formative pulp. 
The deposition of calcoglobulin begins at the outer circumference of the 
pulp, building each time a quoit-like layer, with its rim always at the 
outer circumference of the pulp and its convexity directed towards the 
crown. As fast as the dentin of the root is formed, it is covered by a 
deposition of cement material formed by the cementoblasts lying within 
the developing pericementum or wall of the tooth-follicle. 

Dentinification. — Calcification of the dentin begins at about the six- 
teenth week of intrauterine existence by the formation of a tiny cap or 
layer of calcific material at the tips of the incisors and cuspids (Fig. 168), 
and about a week later in the cusps of the molars. The process begins 
upon the surface of the dentinal bulb or papilla, by the formation of layers 
or lainime, one within the other, the size of the papilla gradually de- 
creasing as each new lamina is formed until it reaches the size prescribed 
for it by nature. 

Some time before the beginning of the process of calcification of the 
dentin there is a layer of cells developed upon the surface of the papilla, 
ovoid in form, and having a long process upon the end, which points 
towards the enamel-organ (Fig. 169). These cells have already been men- 
tioned, and were termed by Waldeyer the odontoblasts or dentin-building 
cells. 

This layer of cells constitutes the membrana eboris of the older writers. 

The form of the odontoblasts varies considerably at different periods of 
the evolution of the dentin. In the early stage, just prior to the commence- 
ment of the process of calcification, the cells are generally ovoid and have 



, f 




Inter- 
globular 
spaces ' 






ss*^ 




NX ^ 



v\\ 



W N 



v\\ 



M 







*' H 



.4... \- 






/ 



-*- 



Fig. 164. — Transverse section of dentin and cementum. 



Interglobular 

d s]>aces, or 
* ^ granular layer 
" Tomes 




Incremental 
lines 



Fig. 165.— Oblique section of enamel and dentin, showing incremental 



(V. A. Latham.) y 




Fig. 166.— Vertical 



Commencing 
formation of 
the root by 
lengthening of 
the pulp 



;tion of face of human embryo, showing the beginning of the formation of the roots 
of the teeth. (V. A. Latham.) X 7. 




Blood-vessels 
and nerves 



Blood-vessels 
and nerves 



Fig. 167.— Section of human lower jaw, showing blood-vessels and nerves at base of the tooth-follicle, and the 
beginning of the formation of the root. (V. A. Latham.) X 9. 



Dental papilla 




Fig. 168.— Vertical section of developing human cuspid, showing early stage of calcification. (V. A. Latham.) 

X 100. 



Pulp 

debris 



v>A.L. 



Fig. 169.— Teased section of de 



Odonto- 
blasts, 
attached 
to formed 
dentin 



' m \ 



^ 



%&£ 



, 




Truncated odon- 
toblasts, showing 
spherule of 
calcoijlobulin 




Fig. 170.— Truncated odontoblasts and fibril cells. (R. R. Andrews.) 



HISTOLOGY OF THE DENTAL TISSUES. 49 

a single process, but during the active stage of development the cells are 
flat and broad, or truncated at the end directed towards the forming- dentin 
(Fig. 170). During this period the odontoblasts often present two or more 
processes ; Boll has counted no less than six, proceeding from a single cell. 
Each cell possesses a single ovoid nucleus, which is located in the end of 
the cell nearest to the dentinal papilla (Fig. 171). The nucleus is some- 
times pointed at the extremity nearest the forming dentin. The body of 
the cell is finely granular, and "Waldeyer and Boll both found the cell 
destitute of any semblance of membrane. The processes of the cells pass 
into the dentinal tubuli, and constitute the dentinal fibrils. 

Stowell (1887) says there are three separate forms of processes arising 
^m each odontoblast : first, those that unite it to its fellow ; second, 
.ose by which it forms its attachment to the connective-tissue cells of the 
pulp proper ; and third, those that pass into the dentinal tubules, the 
dentinal fibrils, the latter as they approach the periphery of the dentin 
branch and finally unite with the cells of the granular layer and the 
cementoblasts. 

After the active stage of dentin formation has passed, the odontoblasts 
again resume their original ovoid form, tapering off to the dentinal process. 

Several theories, more or less divergent, have from time to time been 
advanced as to the process by which the dentin was developed, the main 
int in controversy being the part played by the odontoblasts in this 
orocess. 

Waldeyer, Frey, Boll, Beale, and others support the theory that the 
dentinal fibrils, the sheaths of Neumann and the matrix surrounding them, 
are formed from the odontoblasts by a metamorphosis of these cells, these 
structures representing three stages in the conversion of the same sub- 
stance. Beale expresses it as protoplasm, — the dentinal fibrils ; formed 
material,— the dentinal sheaths ; calcified formed material, — the matrix, the 
completed, fully calcified tissue. 

Yon Ebner has discovered the existence of a delicate fibrillar structure 
in both bone and dentin, and although von Ebner and Eose both believe 
that the whole of the dentin is derived from the odontoblasts, they say their 
axial portions persist as the dentinal fibrils, while their outer portions are 
metamorphosed into a delicate fibrillar gelatinous tissue, a sort of connec- 
tive tissue, which forms the matrix and receives the deposition of the lime- 
salts. 

Tomes says upon this epiestion, "The close relation of these cells to 
the dentin, their change in form according as dentin-building was or was 
not actively going on, their resemblance in position and apparent consist- 
ence to osteoblasts, and the absence of any other of the large cells which 
we associate elsewhere with elaboration of special products, would natu- 
rally lead to the inference that they were the chief factors in the segrega- 
tion of lime-salts and their incorporation in the dentin.*' 

Andrews (1887) called attention to pear-shaped cells, which he termed 
" dentin corpuscles," lying between the square-end odontoblasts so uniformly 
■ present during the active stage of dentin formation (Fig. 172). 

The odontoblasts he considers as simply matrix formers, having nothing 



50 OPERATIVE DENTISTRY. 

whatever to do with the formation of the dentinal fibrils, as they are mem- 
braneless masses of protoplasm, while the pear-shaped cells — u dentin cor- 
puscles" — form the dentinal fibrils by the elongation of their processes, 
and which also possess the important function of nourishing the dentin 
matrix. 

Mr. Mummery, in following still farther the investigations of von Ebner, 
noted the appearance of connective-tissue fibres, or bundles of fibres, just 
in advance of the main line of calcification, which had not been derived 
from the odontoblast, but from the connective- tissue cells of the dentin 
papilla. He discovered further, in young developing teeth, by the aid of 
Koch's method of preparing sections, as modified by Weil, the presence of 
a distinct reticulum of fine connective-tissue fibres, which passed in bun- 
dles between the odontoblasts and enveloped them. Within this reticulum 
he believes the calcium salts are deposited for the building of the dentin 
matrix. He also found other cells than the odontoblasts applied to the 
connective-tissue fibres, both in man and in fish, which recall the cells 
attached to the osteogenetic fibres of bone. 

In view of these discoveries it would seem that the process of calcifica- 
tion of dentin is more nearly like that of bone than has been previously 
supposed, and if Mr. Mummery is right, the question very naturally arises 
as to the actual part taken by the odontoblasts in the formation of the den- 
tin. It would seem, however, that the fact is fairly well established that 
the odontoblasts form the dentinal fibrils by the elongation of their pro- 
cesses, and that they are the active agents in the development of the dental 
tubuli ; but whether the odontoblasts or the cells of Mummery superintend 
the elaboration and deposition of the calcific material to form the dentin 
is a matter of doubt, and farther investigation will be necessary before the 
question can be settled. 

Andrews, in speaking of the odontoblasts and the pear-shaped cells 
described by Mummery, says, u The odontoblasts are masses of protoplasm, 
without membranes, and are at a certain stage of growth square and abrupt 
against the matrix. It is an easy matter to find among them, and immedi- 
ately adjacent, large numbers of pear-shaped cells, tapering into the denti- 
nal fibril. The odontoblasts, when calcification is active, are scarcely more 
than masses of protoplasm, filled with minute globules. The fibrils which 
appear to come from them are described by Tomes under three divisions, 
— viz., "pulp, lateral, and dentin processes, 11 which originate probably from 
a fibril-forming cell. These pass through the soft substance of the odonto- 
blasts (protoplasm), and seem to be a part of them, but in fresh, young 
sections the so-called processes move in the substance of the odontoblasts 
by pressure of the cover-glass, and the fibril may be traced to a pear-shaped 
cell beyond. There will usually be found as many processes going out 
from the sides and ends of the odontoblasts towards the pulp as there are 
going into the matrix from the dentin end of the cell. In cross-sections 
of the odontoblasts, delicate, light spots are seen in the substance, which 
are probably the cut fibres. When the layer of odontoblasts is teased 
away from the forming dentin, fibrils are seen bridging the gap, apparently 
off-shoots from the odontoblasts ; but on careful examination there will 



Stellate reticulu 



Formed enamel 



Truncated ends 
of odontoblasts 



Formed dentin 



Odontoblastic 




■apillii 



Fig. 171.— Section of tooth-follicle (human), showing the nuclei of the odontoblasts and of the ameloblasts, 
and the truncated ends of these cells. (V. C. Latham.) >< 325. 



j M 1 




Fig. 172.— Odontoblasts, showing truncated cells and pear-shaped bodies lying between the dentin corpuscles. 

(R. R. Andrews.) 



Lacunpe and 
eanaliculi 




Fig. 17:;.— Bone, showing Haversian system, lacunae, and eanaliculi. 



W-**' 








H*Ej[£*. y* V 




1 t *£*• 


&%^% 


fc$ ^: 




< s V v w j ~~^ 


— >> ' "•■ ^'is»= 







''~Ai£*-, 





Fig. 174. — Transverse section of human femur, mature bone. X 60. 



HISTOLOGY OF THE DENTAL TISSUES. 51 

usually be fouud a decided line of demarcation across the fibre at tlie point 
where it meets the square end of the odontoblast. This line seems to show 
that the fibril was not continuous with the protox3lasm of the cell. Other 
sections which have been separated by teasing, show odontoblasts having 
their side masses of protoplasm drawn away from the fibril which appar- 
ently has run through it. Some of this protoplasm is left upon the fibril, 
giving it a ragged appearance as it passes from a canal in the matrix acinus 
to the separated pulp-tissue, bridging the gap. 

The pear-shaped cell has perhaps a more important function than the 
odontoblast proper. It is to supply the life and nourishment to the whole 
of the calcified matrix, as the bone-corpuscle within its " lacuna supplies 
life and nourishment to bone and cementum." 

One of the strongest arguments, however, in support of the older 
theory that the odontoblasts elaborate or secrete the calcium salts and 
superintend the deposition of this material in the formation of the dentin 
matrix, is the fact that calcospherites of different sizes are found in these 
cells during the active stage of calcification. 

Eobin and Magitot noted the presence of globular spherical forms— 
calcospherites — in the young pulps of human teeth. Henle also discovered 
them in the young tooth-pulps of the herbivora, as did also Eobin and 
Magitot, 

In the early history of the dentinal papilla, just before the beginning 
of calcification, numerous globular, glistening bodies — calcospherites — are 
to be seen in the papilla and within the odontoblasts, but most abundantly 
upon the surface of the papilla next to the inner tunic of the enamel- 
organ, just where the first layer of dentin is to be formed. 

The calcospherites are seen to collect in large numbers at this point, 
where they arrange themselves in groups and coalesce to form larger glob- 
ules of calcoglobulin, as already described. These again melt together to 
form the first layer of dentin, the matrix forming around the processes of 
the odontoblasts, which recede as each additional layer of dentin is laid 
down, the processes of the odontoblasts elongating to accommodate the 
increasing thickness of the dentin matrix. 

AVhat becomes of the superabundance of odontoblasts resulting from 
the continual decrease in the size of the dentin r^apilla during the forma- 
tion of the dentin is a question that the author does not remember to have 
seen or heard discussed. It is a well-established fact that, as a rule, cells 
and tissues which have performed their functions, and for which nature 
has no further use, either atrophy or disintegrate, are resolved into their 
original elements, and are then absorbed. This may be the process by 
which the used-up cells are removed in the formative pulp. But in seek- 
ing an explanation of the modus operandi by which the tubules of the 
dentin become branched, it has occurred to the author that certain of the 
odontoblasts may coalesce from time to time as the decrease in the size of 
the papilla makes it necessary for their numbers to be lessened, thus form- 
ing branching dentinal processes around which the dentin matrix is 
formed, the larger fibril or main trunk representing the persistent odonto- 
blast, while the branches represent the fibrils of the cells which have been 



52 OPERATIVE DENTISTRY. 

merged into the persisting cell. This would also explain the presence of 
the odontoblasts having multiple processes which are so common during 
the active stage of dentin formation. 

The presence of the transverse processes which seem to unite the odon- 
toblasts laterally may be explained by the recent discovery of von Ebner 
and Mummery of a connective-tissue net- work of fibres passing between 
and surrounding the odontoblasts, and just in advance of the main line of 
calcification. 

CEMENTUM. 

Cementum, or crusta petrosa, is a specialized product of specialized 
osteoblasts or bone-producing cells, the cementoblasts. 

Mature cementum, chemically and physically, is very little different 
from the compact tissue of bone, with the exception that it is generally 
devoid of Haversian canals. Figs. 173 and 174 show the structure of mature 
bone. 

Cementum is the external covering of the roots of the teeth. . In many 
animals it also forms a part of the covering of the crown, being associated 
with the enamel in separate vertical laminae. 

The cementum begins at the neck of the tooth, at the free margin of 
the enamel, in a thin layer (Fig. 175), and gradually increases in thickness 
towards the apex of the root (Figs. 176 and 177). In teeth with roots 
closely associated the cementum often extends from one root to the other, 
resulting in a firm osseous union. 

The cementum is thicker in adult life than in childhood, and in aged 
people it is thicker than in adult life. Black thinks it grows at intervals 
during the life of the individual. 

Histologically it is composed of a matrix consisting of a gelatinous sub- 
stance combined with the salts of lime. AYithin the matrix are numerous 
little hollow spaces, the lacunae, filled with protoplasmic substance, and 
from which branch in all directions many minute processes, the canaliculi ; 
these often anastomose with neighboring canaliculi and with the inter- 
granular layer (Fig. 178). 

The matrix is composed of collagenous fibrils in fine or coarse bundles, 
combined with calcium salts, and j)ernieated by vascular canals in the 
thicker portions near the apex of the root. These vascular canals corre- 
spond to the Haversian canals of bone. Like bone, when boiled it yields 
gelatin, and when decalcified it retains its form. At times it appears to 
be structureless ; at others finely granular or interspersed with small 
globules (Tomes). 

The matrix is laminated in structure, the incremental lines running 
parallel to the long axis of the tooth ; but, although the cementum is thin 
at the cervix and thick at the apex, the number of lamellae is about the 
same in all parts of the tissue. 

The lacunce in dried sections are irregular cavities with their long axis 
corresponding to the long axis of the tooth. The processes are given off 
most frequently at right angles to the direction of the lamellae, and most 
abundantly upon that side towards the exterior surface of the root. The 
size and form of the lacunae in cementum are very variable, while the 




Fig. 175. — Transverse section of human cuspid, at cervix. X 150. 



Dentin 
Pulp-cavity 





Fig. 176.— Longitudinal section of young cuspid. Fig. 177.— Longitudinal section of young molar. 




Fig. 178.— Transverse section of apex of human molar. X 9" 




Fig. 179.— Longitui 
(F. B. Noyes.) X SO. 
periosteum; F' , fibres 



inal section of root of tooth and alveolus, sli 
D, dentin; C, C, cementum ; F, fibres passir 
to bone (Sharpey's fibres). 



Hies of root and alveolus in siht. 
Ige of process to outer layer of 



Alveolar proee 



&M 



#1* 



? 7 



. V ', " I, .' : Sharpey's fibres 



''%■ 



Pericementum 



Alveolar process 



Mki 



tfl 



Fig. 180. — "Vertical section of human alveolar process and cuspid tooth in situ. (V. A. Latham.) X 100. 




Fig. 181.— Developing bone from human scapula. (V.A.Latham.) X 50. 



HISTOLOGY OF THE DENTAL TISSUES. 53 

number and length of their processes are excessive when compared with 
bone. 

The lacunae are formed by cementoblasts or nests of cementoblasts, 
which have been encapsuled during the process of calcification, but which 
have maintained their individuality. These are sometimes termed cement- 
corpuscles. 

Sharpey's fibres are found in the cementum, having the appearance of 
rods which run through its substance. They are composed of connective- 
tissue fibres, and form the medium of connection between the alveolo-dental 
membrane, or pericementum, and the cementum. Figs. 179 and 180 show 
Sharpey's fibres in the alveolar process. 

The dentin and the cementum are inseparably connected through 
the medium of the granular layer of the dentin, the fusion of the two 
tissues being so complete that the line of union is often difficult or well- 
nigh impossible to make out. 

CEMENTIFICATION. 

According to the common classification adopted by writers upon ossifi- 
cation, the methods by which bone is formed are stated as follows : 1, in- 
tracartilaginous or enchondral ; 2, subperiosteal ; and 3, intramembranous ; 
but the essential nature of the process is the same in all. 

In the intracartilaginous method the bone is first formed or preformed 
in cartilage (Fig. 181). In the subperiosteal the bone has not been pre- 
formed by the cartilage, but the tissue in which the bone is to be formed 
is fibrous and vascular ; osteoblasts appear along the bundles of fibres 
beneath the periosteum, which become calcified, and bone is formed 
around them (Stedman) by the deposition of calcoglobulin, as already de- 
scribed. Many of the fibrous bundles persist in the formed bone as 
Sharpey's fibres, while in the intramembranous form the bone is devel- 
oped, as in the cranial bones, from a preceding membranous structure. 
Sudduth adds a fourth, interstitial, a division of the intramembranous 
group, which he thinks is necessary to explain the method by which the 
inaxillse are formed. He claims that osteoblasts are found in the embry- 
onal tissue of the future maxillary bones "before there are any indications 
of a condensation of the connective tissue into a membrane such as is found 
when ossification first begins in the skull-cap. A few osteoblasts, inde- 
pendent of the influence of either membrane or periosteum, arrange them- 
selves in groups here and there. These groups are the points of ossifica- 
tion, and from them the process extends as the jaw develops." The bone 
formed in this manner is provisional bone, and is later removed by internal 
resorption, as is the case with all foetal bone, and replaced by a permanent 
bone formation. 

Cementification is a slightly modified form of subperiosteal ossification. 
We have seen in our study of the origin and development of the teeth that 
the enamel-organ and the dentin bulb were enclosed within a sac or- follicle. 

Calcification of the enamel and dentin has progressed within this 
follicle, but the walls of the follicle have taken no part in the process. In 
the formation of the root the follicle takes an active part by becoming the 



54 



OPERATIVE DENTISTRY. 



cement organ. The walls of the follicle are composed of two layers. The 
outer layer is a dense, firm, fibrous structure, while the inner layer is thin, 
frail, and somewhat transparent ; both are supplied with a rich net- work 
of blood-vessels. 

From the outer layer of the follicular wall the alveolo-dental perios- 
teum, or pericementum, is developed, while from the inner layer are formed 
the cementoblasts, which are speedily converted into cementum. 

The dentin of the root is in most part formed during the passage of the 
crown from its bony crypt and eruption through the gum. The process 
of building the root is from the outer circumference towards the centre : 
the diameter of the root is thus fixed by the outer layer of the dentin, 
while the increase in length is by extension. The formation of the 
cementum, like that of the enamel, is from within outward ; the first 
layer of the cementum being deposited upon the outer circumference or 
periphery of the dentin of the root ; upon this layer is deposited another, 
and so on uutil the typal thickness is reached and the cement-tissue is 
completely formed. 

The following table by Underwood will be found valuable as a ready 
reference of the composition of the various calcified dental tissues and 
their comparison with bone : 

CHEMICAL COMPOSITION OF THE CALCIFIED TISSUES (APPROXIMATE 

TABLE). 





Adult 

Enamel. 


Infantile 
Enamel. 


Adult 
Dentin. 


Adult 
Cementum. 


Adult 
Bone. 




Per cent. 
3.50 
88.00 
4.50 
2.00 
1.50 
0.50 


Per cent. 
15.50 
75.50 
7.00 
2.00 
1.50 
0.50 


Per cent. 
28.00 
64.50 
3.50 
2.00 
1.50 
0.50 


Per cent. 
32.00 
57.00' 
7.00 
2.00 
1.50 
0.50 


Per cent. 
33.50 




51 00 


Calcium carbonate 


11.50 
2.00 


Magnesium phosphate 


1.50 
50 








100.00 


100.00 


100.00 


100.00 


100.00 



It will be seen the amount of organic matter varies considerably be- 
tween infancy and adult life. Galippe (Journal British Dental Association, 
1886, p. 361) has a very exhaustive paper on the chemical composition of 
the teeth. 

Hoppe-Seyler has found in the enamel of the new-born child as much 
as 22.29 per cent, of organic matter, 9.71 per cent, in the young pig, and 
in the fossil rhinoceros 3.16 per cent. Bibra gives two per cent, of organic 
matter in the adult male and five per cent, in the adult female. 



NASMYTH'S MEMBRANE. 

The origin and function of Nasmyth's membrane has furnished matter 
for a considerable difference of opinion and much speculation. Tomes 
and Magitot regard it as a thin covering of cementum, as it is similar to 
and continuous with the cementum covering the root, lacunee being found 
in its substance. 




Outer layer 
of columnar 
Is 



Inner layer 
of columnar 



-Vertical section of human enamel and Nasmyth „ u 
of what appears to be two layers of columnar epithelial cells. (V. A. Latham.) x 250. 



lbrane, showing the latter to be composed 







«• «.* „. 



vv 



,*'</ v 



-><t >»•, • 







Fig. 183. — Section of normal pulp-tissue, showing its various forms of cells and the hair-like processes. 
(V. A. Latham.) X 113. 




Fig. 181. — Section of normal pulp-tissue, showing odontoblastic layer. (V. A. Latham.) X 145. 



m 




185.— Injected Wood-vessels of the 
pulp. (After Stowell.) 



Fig. 186.— Vertical section of developing teeth of kitten. Injected 
to show blood-supply of pulp. (V. A. Latham.) )< 10. 




Fig. 187.— Vertical section 



duous molar in situ. Inji 
(V. A. Latham.) X , r >0. 



HISTOLOGY OF THE DENTAL TISSUES. 55 

Huxley, Kolliker, Waldeyer, and Rose have each maintained that the 
cuticulq dentis was derived from the epithelium of the enamel organ, 
Waldeyer stating that it was the product of the outer tunic of the enamel 
organ. 

Paul (1896) has shown that the membrane was composed of flat epi- 
thelial cells. These could come from no other source than some part of 
the enamel-organ, probably from the outer tunic. Paul suggests that its 
function is to protect the enamel from the action of acids. C. S. Tomes, 
who formerly held the view of his father, now agrees substantially with 
Paul. He says, ' ' The more recent investigations of Dr. Paul have thrown 
a fresh light upon the matter, and have shown that the points upon which 
I chiefly relied are susceptible of quite a different explanation." 

Sudduth thinks it is derived from a metamorphosis of the ameloblastic 
layer, the prismatic cells of which assume a horizontal direction. Mrs. 
Emily Xunn Whitman has noted these changes in studying the develop- 
ment of the teeth of the rat and the rabbit, and has ' ' traced the gradual 
transition of the enamel-rods into a perfectly homogeneous membrane, the 
cylindrical cells growing shorter and shorter as they approached the sur- 
face of the crown, until, instead of being columnar, they are almost square, 
and finally flattened, while at the last the outlines of the cells quite disap- 
pear, and there is left a perfectly homogeneous membrane." 

From the appearances in the illustration (Fig. 182) of a vertical section 
of the enamel and Nasniyth's membrane, it would seem that it was un- 
doubtedly formed from the outer tunic of the enamel-organ, and that the 
columnar character of the cells was maintained in the formation of the mem- 
brane. It will be noticed by a reference to the illustration that in this case 
the membrane is composed of two layers of columnar cells superimposed 
one above the other. The section illustrated was taken from a depression 
in the surface of the enamel where it would be protected from wear. This 
membrane, from its resistance to acids and alkalies, putrefaction, boiling, 
etc. , would seem to be composed of the same substance as the matrix of 
dentin. 

THE TOOTH-PULP. 

The pidpa dentis, the organ occupying the central cavity or pulp-cham- 
ber of a mature tooth, is the remnant of the formative organ of the den- 
tinal tissue, and the source of the nutrition and nerve supply of the fully 
formed dentin. 

The tooth-pulp, which is often erroneously termed the "nerve," is 
conq^osed of a very delicate connective tissue, nucleated cells, blood-ves- 
sels, and nerves, while in general outline it corresponds very closely to the 
exterior form of the tooth. The matrix, or basis substance of the pulp, is 
composed largely of a kind of undeveloped soft connective tissue, possibly 
belonging to the mucous or gelatinous species containing numerous cellular 
elements (Ziegler) of rounded, oval, and spindle forms, with slender, hair- 
like processes (Fig. 183). 

The interspaces between the fibres are large and filled with a jelly-like 
material, which gives it an appearance common to many forms of embry- 
onic tissue. 



56 OPERATIVE DENTISTRY. 

The cells of the pulp are fairly abundant, but not sufficiently numerous 
to form a tissue of themselves ; they are found scattered throughout the 
matrix, embedded in the jelly-like material within the interspaces, and 
upon the periphery. 

The form and distribution of the cells varies very considerably in 
different parts of the pulp. In the deeper coronal portions the cells are 
not numerous ; they may be spheroidal, oval, or spindle-shaped, and have 
no definite order or relations to each other, while in that portion within 
the root- canals the cells are arranged parallel with each other and with 
the root. As the periphery of the pulp is approached the arrangement of 
the cells becomes more orderly, many cells having three or more processes 
are seen, some extending towards the pulp, while the others are directed 
towards the dentin and pass between the odontoblasts. The last-named 
cells — the odontoblasts — are arranged in a definite order, side by side, in a 
single layer over the whole periphery of the pulp, covering it as with a 
delicate membrane or epithelium (Fig. 1S4). The odontoblasts are fur- 
nished with three sets of processes, as already described, one set con- 
necting it with its fellows, another with the connective tissue of the pulp 
proper, and a third which pass into the dentinal tubuli. 

The blood-vessels of the pulp are numerous ; three or more arteries 
often enter at the apical foramen, divide into innumerable branches, and 
form an extensive net- work, as shown in Fig. 185, terminating in a rich 
capillary plexus beneath the layer of odontoblastic cells. 
This is well illustrated in Fig. 186, made from a section of 
the jaw and developing teeth of a kitten injected for this 
purpose. The veins are also numerous and somewhat larger 
than the arteries. The blood-supply, however, is better 
shown in Fig. 187, which is made from an injected human 
decidulous molar. They form frequent anastomoses near 
the surface, as shown in Fig. 188, which is also made from 
an injected specimen. Lymphatics have never been demon- 
strated in the pulp. 

The nerves of the pulp enter the apical foramen either 
in a simple large trunk or by several smaller ones. They 
pursue a parallel course, giving off but few branches until 
NerVeS p uip dental the P^lp-chamber is reached, when they divide into numer- 
ous branches, going in all directions, and forming a minute 
net- work just beneath the odontoblasts, where they end in non-medullated 
fibres (Fig. 189). Many terminal fibres pass between the odontoblasts to 
the dentin ; but the final distribution of the fibres has never been satisfac- 
torily demonstrated. 

THE PERIDENTAL MEMBRANE. 

The peridental membrane, pericementum, or the alveolo- dental perios- 
teum (Fig. 190), is a -fibrous connective-tissue structure which covers or 
invests the root of the tooth from the cervix to the apical foramen (Fig. 
191), just as the periosteum invests the bones (Fig. 192) and lines the 
walls of the alveoli, having few elastic fibres, and richly supplied with 





lvrirriiiciitimi 



lveolar procc 



Peneeruentm 



Fig. 190. — Section of jaw of field-mouse, showing pericementum and alveolai 
(V.A.Latham.) > 100. 



Mveolar proce;; 



_-ss between the teeth. 



Blood- 
vessels 




Odonto- 
blastic 
layer 



Transverse section through pulp-chamber of human cuspid tooth. 




Jl 



_ . .. / 



■'. 



■J 



..iy 



4 



'.-Transverse section of forearm of a child, showing periosteum surrounding the bones. X 13. 



Peridental 
membrane 




Fig. 193.— Transverse section through roots of forming tooth of fielcUmous 
dipping in between the roots. (V. A. Latham.) 



M 



v4kjfl 







-1 ; 



i^^p^ 







-- ' 



Blood- 
vessel 



_-- -■ - Forming 

^*mi ( ' emen - 

' ,«JT turn 




Fig. 194.— Transverse Section of developing tooth of field-mouse at base of the dentin papilla-, showing peri- 
dental membrane. (V. A. Latham.) X "5. 




195.— Transverse section of jaw through alveolar process, showing tissues of root and alveolus in situ. 
(F. B. Noyes.) X 30. E, epithelium ; F, subepithelial connective tissue ; B, point where pericementum fibres 
are lost in fibrous mat of gum ; F', fibres extending from tooth to tooth (Sharpey's fibres) ; P, pulp. 




^ 






-:tr 



f/. 



wm 






7 

1 



wi 



Uc 



/■ 



n 






v? 



^ 



Fig. 196.— Longitudinal section of root of tooth in situ, showing relation of the tissues and Sharpey's 
fibres in the alveolar process. (F. B. Noyes.) 2), dentin ; N, Nasmyth's membrane ; C, C, cementum ; F, 
fibres supporting gingivus ; F 1 , fibres joining the outer layer of periosteum over the alveolar process 
(Sharpey's fibres) ; F-, fibres running from cementum to bone ; B, bone or alveolar process. 



1 



Turning under of 
the base of the 
enamel-organ 




Fig. 197.— Vertical section of a dental follicle, showing the blood-vessels and nerves entering at the base of the follicle 
and a peculiar turning under of the enamei-organ at the base of the dental papillae. (V. A. Latham.) X 96. 









Eb 




E 






E 

E 


Ik ^n 


Cb 
C 

n 



Fig. 198.— Section of pericementum in situ, showing epithelial bodies. (F. B. Noyes.) X 408. D, dentin ; C, cementum; 
Cb, cementoblasts ; Fb, fibroblasts ; E, E, E, epithelial structures. 



HISTOLOGY OF THE DENTAL TISSUES. 57 

vessels and nerves. It is in reality periosteum, slightly modified to adapt 
it to its environment and special functions. 

The peridental membrane is derived from the sacculus of the dental 
follicle. It is continuous with the periosteum of the alveolar process, and 
appears to he a reflection of this membrane, to line the walls of the alveoli 
and invest the root of the tooth. Fig. 193 shows the membrane at an 
early developmental period dipping in between the forming roots of the 
tooth of a field-mouse. 

The dental sacculus is composed of two layers, the external being made 
up of a fairly dense fibrous connective-tissue structure, while the internal 
layer is rich in cellular elements and retains a softer and more embryonic 
character. The external layer upon the eruption of the tooth becomes the 
j)eridental membrane, while the internal layer furnishes the cellular ele- 
ments for the formation of the cementum (Fig. 194) ; in other words, it 
becomes the cement organ. 

The pericementum is a single membrane common to the cementum and 
the alveolar wall. There is no evidence whatever of a double membrane. 

The peridental membrane of a mature tooth is thickest near the cervix 
and at the apex of the root. The general direction of its fibres is trans- 
verse ; in other words, they run through the thickness of the membrane 
from the cementum to the alveolar wall (Fig. 195). The attachment of the 
pericementum is increased by the presence of bundles of fibres, — Sharpey's 
fibres, — which penetrate the bone upon the one side and the cementum 
upon the other (Fig. 196), but in general the membrane is more strongly 
adherent to the cementum than to the walls of the alveolus. Sharpey's 
fibres are found most abundant at the cervix. ''They are white connec- 
tive-tissue fibres, the ends of which are included in the matrix of the cemen- 
tum sufficiently to make them ai^parent when the lime-salts are removed, 
but when both are calcified they cannot be demonstrated except in cases 
where there is imperfect calcification of the fibres" (Black). 

The functions of the pericementum are fivefold, — viz., first, by its 
cementoblasts to form the cement-tissue ; second, to furnish connection 
and attachment of the root to its alveolus ; third, to act as an elastic 
cushion or buffer between the root and the alveolus, thus providing against 
injury from the severe concussion and lateral strain incident to mastica- 
tion ; fourth, to provide nutrition for the cementum through its abundant 
vascular supply ; and fifth, to give sensation to the cementum and the 
tactile sense to the tooth through its plexus of nerves. 

The blood- supply of the pericementum is derived from two sources, the 
principal one being the main artery entering the deepest point of the alve- 
olus (Fig. 197). This, entering the thicker portion of the membrane at 
the apex of the root, divides into several branches, one or more of which 
pass through the membrane and enter the apical foramen to supply the 
pulp ; while the others are distributed to the substance of the pericemen- 
tum, and through their capillaries furnish nutrition to the cementum. 
Numerous minute branches derived from the blood-vessels of the alveolus 
also penetrate the membrane and freely anastomose with the vessels 
derived from the apical plexus. 



58 OPERATIVE DENTISTRY. 

Wedl says the vascular supply is derived from three sources : the gums, 
the vessels of the bone, aud the vessels destined for the pulp of the tooth, 
the last being the most important. 

Black has recently demonstrated the presence of certain bodies, of 
epithelial structure (Fig. 198), which from their form and location he is 
inclined to believe are lymph-glands lying within the pericementum ; he 
describes them as being lobulated in form, and filled with lymphoid cells. 
These gland-like bodies are beautifully shown in the accompanying photo- 
micrographs (Figs. 199 and 200), prepared by Professor F. B. Noyes, of 
the Northwestern University Dental School. Black was unable, however, 
to fully demonstrate the existence of a duct or channel leading from any 
of the glands. 

The nerve-supply of the pericementum is from two sources, and is dis- 
tributed in a manner similar to that of the blood-supply. The principal 
source of nerve-supply is from the dental nerve ; a single branch is given 
off, which enters the alveolus with the blood-vessels, where it divides into 
several filaments, a portion going to the pulp and the others being distrib- 
uted to the pericementum ; numerous other filaments enter the membrane 
from various minute channels in the alveolar walls and the intervening 
septa to unite with those derived from the dental nerve. 

The vital connection of the human tooth with the living organism is 
very intimate, being abundantly supplied with blood-vessels and nerves, 
both to its pulp and pericementum. 

Tomes, referring to this, says, "The dentin is organically connected 
with the pulp by the dentinal fibrils ; these are connected with the soft 
cement- corpuscles, which again are brought by their processes into inti- 
mate relation with similar bodies in the highly vascular periosteum, so that 
between the pulp on the inside and the periosteum on the outside there is 
a continuous change of living plasm." 

THE GUMS. 

The gums, or gingiva?, are formed of a layer of tough, fibrous, non-elastic, 
vascular connective tissue (Fig. 201) covering the alveolar processes, being 
closely associated with the periosteum, the fibres of which intercommuni- 
cate, and covered with the common mucous membrane of the mouth 
(Fig. 202). It unites with the pericementum at the cervix of the tooth 
without any line of demarcation. Numerous papillae are present, single 
and compound. The gum-tissue is abundantly supplied with blood-vessels, 
but nerve-filaments are rarely found. Lobulated glandular structures are 
to be seen ; these are the glands of Serres (Fig. 203). 

The margins of the gums closely invest the necks of the teeth, forming 
festoons which occupy the interapproximal spaces. 

The epithelium of the mucous membrane covering the gum is com- 
posed of a dense laminse of tessellated cells, which are derived from the 
deeper layer of columnar cells, — the rete Malpighii (Fig. 204). The epi- 
thelium is very tough and hard. This fits it in a remarkable degree to 
withstand the severe abrading action of certain forms of food during their 
mastication. 







-Section of peridental membrane, showing epithelial bodies or glandular structures. (F. B. Noyes.) 
700. D, dentin; C, cementum; Cb, cementoblasts; E, epithelial bodies; F, F, white fibres. 




— ,6'fc 






^V 







Fig. 200.— Section of peridental membrane, showing epithelial bodies or glandular structures. (F. B. Noyes.) 
X 900. I), dentin ; C, ceruentum ; Cb, cementoblasts ; E, epithelial bodies ; F, white fibres. 




Mucous membrane 



Alveolar process 



IVririinentum 



Fig. 201.— Transverse section of the jaw through the mucous membra 
(V. A. Latham.) • 60. 



m, and alveolar process. 



Mucous membrane and epitheliur 




Fig. 202.— Oblique section of dental follicle and mucous membrane. (V. A.Latham.) 20. 




lands of Serres. X 50. 




Fig. 204.— Epithelial layer of mucous membrane in its embryonic stage. A, squamous epithelial cells 
B, columnar cells— rete Malpighii. 



CHAPTER IV. 

ERUPTION OF THE TEETH. 

Definition. — The process by which the teeth advance from the bony 
crypts, in which they have undergone the calcification of their crowns 
and a portion of their roots, and are forced through the gums. 

Synonymes. — Teething; cutting the teeth ; dentition. 

Dentition is a physiologic process having no counterpart in the growth 
of other tissues. Fig. 205 represents a tooth in the process of eruption, the 
nearest approach to like conditions being the emergence of the hair-sheaths 
and the nails. In this use of the term dentition it will be understood that 
it has no reference to the process of development of the germs of the teeth, 
but refers only to the process of eruption. Fig. 206, made from a section 
of the jaw of a young rabbit, and Fig. 207, made from a section of the 
foetal jaw of a field-mouse, show the relation of the primary and secondary 
teeth to each other at the period of the eruption of the primary teeth. 

The process of dentition is divided into primary, the eruption of the 
deciduous or milk-teeth, and secondary, the eruption of the permanent 
teeth. 

Normal primary or deciduous dentition begins between the fifth and 
eighth months after birth, and terminates between the twenty-fourth and 
thirty-second months. The following table represents the average period 
of the eruption of the various classes of teeth which constitute the tempo- 
rary denture : 

The central incisors from 5 to 8 months after birth. 

The lateral incisors from 7 to 10 months after birth. 

The first molars from 12 to 16 months after birth. 

The cuspids from 14 to 20 months after birth. 

The second molars from 20 to 32 months after birth. 

The inferior teeth usually appear a few weeks in advance of the supe- 
rior. iSTo general rule can be formulated from which, however, there will 
not be marked and frequent deviations. The variations are so marked in 
the dates of the eruption of the teeth that no two authors give them exactly 
alike. Tubercular and syphilitic children erupt their teeth very early, 
while in rhachitic children the process begins very late. 

It has been stated that Richard Coeur de Lion of England and Louis 
XIV. of France were born each with several teeth. 

It is not a very uncommon occurrence for children to be born with 
teeth. Haller, in his "Elements of Physiology," mentions nineteen cases 
of children that were born with one or more teeth fnlly erupted. 

The author has several times been called upon to remove teeth from the 
mouths of newly born infants, and there are few physicians or dentists of 

59 



60 OPERATIVE DENTISTRY. 

twenty or twenty-five years' practice who have not had a similar expe- 
rience. 

Crump reported to the Virginia Society of Dentists a case of full denti- 
tion in a child at birth (Pepper) ; while, upon the other hand, the teeth are 
sometimes entirely suppressed. 

Boxalli and Bauro.es have each recorded a case in which the individual 
reached old age without a single tooth ever having appeared. A few years 
ago a Eussian family, father and young son, were on exhibition before 
medical and dental societies and in various museums under the name of 
"dog-faced men." The father had no teeth up to the age of seventeen, 
then four teeth appeared in the lower jaw but none in the upper. The son 
had four lower incisor teeth but no evidence of any others. The jaws of 
the father, who was a strong and powerfully built man, were no larger 
than those of his little son. 

The Eruptive Process. — The modus operandi or the character of the 
agencies by which the teeth are stimulated to advance from their bony 
crypts and emerge through the gums has never been satisfactorily demon- 
strated or explained. Several views have been advanced to account for 
the process, but they are all open to serious objections. 

The first, and j>erhaps the oldest, theory is that the tooth is impelled 
from its crypt and through the gum-tissue by mechanical pressure induced by 
the growth or lengthening of the root from additions of dentin at its base. 

Several strong objections can be raised against this view : first, teeth 
with very short or stunted roots — roots which are much shorter than the 
distance from the margin of the gum to the base of the crypt — are often 
erupted ; second, deciduous incisors are not infrequently found erupted at 
birth, or make their appearance a few weeks afterwards, which have very 
little or no roots at all, the crown only being developed ; third, a tooth in 
which the root is completely developed may remain buried in the jaw until 
past middle life, and then make its appearance 5 fourth, normal teeth, 
particularly the superior cuspids, are so located in their bony crypts that 
in the process of the eruption of their crowns the distance travelled greatly 
exceeds in amount the addition made to the length of the root during the 
same period. 

C. S. Tomes says,* "The tooth of a crocodile moves upward, tooth- 
pulp and all, obviously impelled by something different from mere elonga- 
tion ; and my own researches upon the development and succession of 
reptilian teeth clearly show that a force quite independent of increase in 
their length shifts the position of and 'erupts' successive teeth." 

Another theory advanced to account for the process of eruption is me- 
chanical pressure induced by the lengthening of the dentinal papillw or formative 
pulp. The principal objection to this view is the improbability that the 
elongation of a delicate and more or less embryonic structure like the 
formative pulp could produce a sufficient amount of pressure upon the 
tooth- crown at its base to cause resorption of the overlying bony walls of 
its crypt without injury to its own structure, or causing deflection of the 

* Dental Anatomy. 



Crown of timtli 



Forming root 




Fig. 205.— Vertical se 



wing forming root. X 15. 




tooth - 
follicle 



Fig. 206.— Section of jaw of rabbit, showing deciduous teeth and follicles of permanent teeth in situ at the 
period of the eruption of the primary teeth. X 22. 




Developing 



Fig. 207. — Lower jaw of fcetal field-mouse. X 80. 




Fig. 208.— Vertical section of erupting tooth of field-mouse, showing area cf resorption at the cusp of the tooth. X C3 



ERUPTION OF THE TEETH. 61 

apical end, and thus producing crooked roots, which is by no means a gen- 
eral condition. 

Delabarre suggested that the advance of the tooth from its crypt and 
its passage through the gum was effected in precisely the same manner as 
the foetus is expelled from the uterus. He regarded the sac, which he 
claimed was attached above to the gum and below to the neck of the tooth, 
as the active agent in the eruption of the tooth, induced by the contrac- 
tion of its walls, and thus the crown of the tooth was lifted from the base 
of the follicle and ultimately forced through the uncapped crypt and the 
gum. 

This is a very ingenious explanation, and is based upon the supposition 
that there are elastic fibres within the walls of the sac. 

Nasrnyth found the sac to be composed of two layers, the inner lamina 
composed of a layer of cells loosely arranged, with intersx)aces equal to 
one-half the diameter of the cell. This inner lamina he thought partook 
more of the characteristic of a serous than of a mucous membrane. This 
arrangement of the cellular elements of the inner layer is suggestive of 
contractile power and expelling force. 

If elastic fibres could be positively demonstrated as forming a part of 
the structure of the sac, this would be the most rational theory yet ad- 
vanced, as it would be based upon the known and demonstrable physiologic 
function of elastic tissue. In support of this supposition it has been stated 
that inasmuch as in the periosteum elastic fibres are present in that portion 
of the membrane which lies nearest to the bone, being in the form of a fine 
fibrous net-work, that they must also be present in the structure of the 
pericementum, which is very similar to that of the periosteum. Black, 
however, in his researches upon the histology of the pericemental mem- 
brane, was unable to positively demonstrate the presence of elastic fibres. 
He found the membrane to be composed almost entirely of white fibrous 
tissue, but when the white fibres were dissolved by the usual reagents — 
solutions of caustic potash — no elastic fibres could be discovered. 

Another theory presented was that the eruption of the teeth was caused 
by the moulding or building of the alveolus around the roots. This theory 
is easily disposed of by the statement that the alveolus is not formed around 
the root, nor the root completed, until after the tooth has been erupted. 
At the time of the eruption of the tooth the osteoclasts have made an 
opening in the cap of the crypt (Fig. 208) large enough for the crown to 
easily pass ; this leaves a considerable space between the bone and the root, 
which is occupied by the, at this time, thick pericemental membrane. 

The latest theory is that suggested by Constant (Journal British Dental 
Association, 1896), — namely, that the blood-pressure may be the force which 
impels the tooth in its movement from the crypt and through the gum, 
on account of "the difference in the blood-supply of the parts. 

The pulp and the tissues beneath it have a very abundant vascular 
supply, while those above are not so richly endowed. C. S. Tomes, in 
commenting upon this theory, says, "It seems very possible that the 
blood- pressure keeping up a state of general tension may operate to push 
a solid body in any direction in which there is a diminished resistance, 



62 OPERATIVE DENTISTRY. 

to take up, so to speak, any unoccupied space ; but it is difficult to see 
how it could be efficient without some such concomitant action of absorp- 
tion. For the movement of an erupting tooth is not always by any means 
in the direction of its long axis ; for instance, the developing tooth of the 
frog, the newt, or of the crocodile takes a sidewise journey, by which it 
travels underneath the old tooth before it moves upward at all." 

But if its path be prepared by absorption of the structures in its way, 
then it is very possible that the blood- pressure keeping up a certain gen- 
eral tension may suffice to move it along a track of diminishing resistance. 
Mr. Constant's suggestion, with a little modification, is the most plausible 
that has been offered, therefore, as to the actual motive force ; whether it 
will be regarded as a final solution of the question time alone can show." 

What are the forces which set in operation the process of eruption ? is a ques- 
tion which very naturally arises in discussing this phase of the phenomenon 
of the eruption of the teeth. If the lengthening of the root, the elonga- 
tion of the pulp, or the blood-pressure within the pulp are not sufficient 
as mechanical forces to produce the adequate pressure or mechanical irri- 
tation necessary to stimulate the osteoclasts to the performance of their 
function of tearing down the structures which their sister cells, the osteo- 
blasts, had so lately built up, what other force or forces are operative in 
establishing this phenomenon ? It is possible that it is due to some change 
in the nutrition of the walls of the crypt and the gums, induced, perhaps, 
by the withdrawal of a portion of its blood-supply, as a result of the 
greater activity in the growth of the tooth- follicle just preceding and 
during the period covered by the process of the extrusion of the crown. 
In some such change as this in the nutrition of the paft the resorption of 
the alveolus is induced after the extraction of a permanent tooth. 

The whole subject, it will be seen, is far from being satisfactorily set- 
tled, either as to the conditions which induce resorption or the forces which 
are operative in extruding the tooth-crown from its crypt to its normal 
position in the mouth. 

When the formation of the tooth has arrived at that stage in which it is 
ready to be extruded, and this occurs in the deciduous central incisors, 
which are the first to be erupted, at the fifth to the eighth month after 
birth, a very active process of resorption, the result of a low inflammatory 
condition, takes place in the walls of the bony crypt in which the crown 
of the tooth is lodged. This process is most active at the anterior or labial 
wall and the roof of the crypt, by which the upper portion of the sac and 
the bony tissue are removed, as shown in Fig. 209, while the posterior or 
lingual wall remains unchanged, as it is required to form the labial wall 
of the crypt of the successional tooth. Prior to this, however, there is 
formed in the tissues immediately above the bony crypt of the follicle an 
inflammatory area in which resorption vacuoles are formed which gradu- 
ally increase in size. The opening made by this process (Fig. 210) finally 
becomes larger than the diameter of the crown, thus giving it a roomy 
exit ; but as soon as the crown has passed from the crypt and extruded 
through the gum, the process of resorption gives place to that of a deposition 
of new osseous material, which loosely embraces the cervix of the tooth. 




tint; tooth of Ik'M-niouse, showing area of resorption. X 75. 




Inflammatory 
vacuole 



Inflammatory 
area 



!10.— Vertical section of human cuspid. X "5. 



ERUPTION OF THE TEETH. 



63 



Fig. 211. 




Rami at various ages. A, childhood; 
B, adult life ; C, old age. 



Growth of the Jaw.— As the root of the tooth increases in length 
additions to the margin of the alveolus keep pace with it ; and as the 
process is a somewhat rapid one, the increase in the depth of the jaw is 
correspondingly rapid. This phenomenon begins first in the anterior 
portion of the jaw by the eruption of the 
incisor teeth. Later the first molars are 
extruded, and the jaw deepens posteriorly ; 
then the cuspids make their appearance, 
and still later the second molars, producing 
a corresponding deepening of the jaw in 
these locations. During this time there 
has also been a steady lengthening of both 
the horizontal and the ascending rami of 
the mandible, with a considerable change 
in the angle formed by their union. These 
changes progress until adult life is reached, 
when they assume an angle of about forty- 
five degrees. 

In old age, after the teeth are lost, the 
alveolar processes are resorbed, and the 
rami again assume a more obtuse angle, 
approaching that of childhood. (See Fig. 
211.) The changes which occur in the su- 
perior maxilla are similar, so far as the 
deepening and lengthening of the jaw are 

concerned, to those which take place in the growth of the mandible, 
while the retrogressive changes are confined to the resorption of the 
alveolar processes. 

The eruption of the teeth is not a continuous process, as was pointed 
out by Trousseau ; the teeth being erupted in pairs or groups, with vary- 
ing periods of rest between them. 

The deciduous central incisors are the first of the dental series to be 
erupted ; the appearance of these teeth is followed by a period of rest in 
the process of from one to two months ; the lateral incisors are next ex- 
truded, and their appearance is followed by a rest of from five to six 
months. The first molars come next, and these are followed by the cus- 
pids, with a period of inactivity in the process between them of from two 
to four months. The second molars are the last of the deciduous teeth to 
be erupted, and they make their appearance from six to twelve months 
after the extrusion of the cuspid. It will therefore be seen that the whole 
period of time consumed in the eruption of the deciduous teeth is about 
two years, but the actual time occupied by the various groups of teeth in 
the passage from their bony crypts and through the gum to their normal 
positions in the mouth is much less than this ; the usual period of time 
consumed by each group is only from four to eight weeks. 

The roots of the deciduous teeth are completed in formation at about 
the following periods and in the order named, but no positive rule can be 
laid down from which frequent deviations will not be observed : 



64 OPERATIVE DENTISTRY. 

The central incisors are completed at about the age of 2 years. 

The lateral incisors are completed at about the age of 2 J years. 

The first molars are completed at about the age of 2} years. 

The cuspids are completed at about the age of 2 3 years. 

The second molars are completed at about the age of 3 years. 

Fig. 212 shows the jaws of a child at three to three and a half years of 
age. 

MORBID PRIMARY DENTITION. 

The eruption of the teeth in a normal child is productive of so little 
general or local disturbance that many times the teeth make their appear- 
ance within the mouth before the parent or nurse have realized the fact 
that the process of "teething" had really begun ; while, upon the other 
hand, in children with impaired health and low vitality it often plays a 



Fio. 212. 



■ ■':.- 




Jaws of a child of three to three and a half years of age. 



prominent part in exciting various morbid conditions of the digestive, 
nervous, respiratory, and dermal systems. The subject becomes, therefore, 
one of considerable interest, alike to the general practitioner and to the 
dental specialist. There is no doubt that the dangers from dentition have 
been greatly exaggerated by some authorities, and that parents are often 
unnecessarily anxious for their offspring during this period ; yet it must be 
borne in mind that in certain temperaments and under various physical 
conditions and environment there is a real degree of danger present, and 
that morbid phenomena are sometimes excited which may progress to a 
fatal termination. 

According to the mortality tables of London, as cited by West, denti- 
tion was assigned as the cause of death of 4.8 per cent, of all children 



Ix-ciduous tooth 




Follicle of 
permanent tooth 



Fig. 213. — Vertical section of jaw of embryo cat, showing deciduous tooth and follicle of permanent tooth. X ' 




Fig. 21 1.— Oblique section of jaw of embryo cat, showing deciduous tooth and follicle of permanent tooth. X > c 0. 



ERUPTION OF THE TEETH. 65 

dying under one year of age, and 7.3 per cent, of those who died between 
the ages of one and three years. 

The dangers surrounding the period of dentition are much greater in 
large cities and in overcrowded localities, particularly among the middle 
and lower classes of society, than in the suburban and county districts. 
But the greatest mortality is in the foundling hospitals and in overcrowded 
and filthy tenements. 

It therefore becomes a question of how much of this mortality is really 
due to the nervous irritation induced by the eruption of the teeth, or to 
other concomitant causes. Errors in diagnosis of abnormal conditions oc- 
curring at this i^eriod are by no means uncommon, and it is to be feared that 
dentition is sometimes made the scapegoat for the ignorance of a medical or 
dental attendant, or the carelessness or indiscretions of the parents or nurse. 

Contemporaneously with the eruption of the teeth there is a very im- 
portant developmental process taking place in the follicular or glandular 
apparatus of the whole alimentary canal, in preparation for the necessary 
change soon to take place in the character of the food. 

This is a physiologic process, and under'normal conditions, when all 
of the functions of the body are nicely balanced, progresses without any 
disturbance of the general health ; but under opposite conditions it may be 
productive of serious gastric and intestinal complications, the causes of 
which are often entirely overlooked, and the disturbances which are the 
result of this process are attributed to morbid dentition. 

The nervous system of the child at this period is also very impressible, 
the cerebro-spinal apparatus predominating to such an extent that slight 
irritations of almost any character, in children of certain temperaments, 
may be followed by more or less general systemic disturbance, with eleva- 
tion of temperature, vomiting, diarrhoea, bronchitis, and other catarrhal 
conditions, or reflex nervous phenomena, like strabismus, twitching of the 
facial muscles, rolling of the eyes, convulsions, or meningitis. 

Dental Irritation. — The nervous irritation accompanying the erup- 
tion of the deciduous teeth may be caused by one or all of the following 
conditions : 

1. By the very active evolutionary process going on within the jaws at 
this period. 

2. By the lateral pressure induced within the jaws by the contempora- 
neous evolution of two sets of teeth. 

3. By peripheral irritation of the gingival nerves from the pressure of 
the advancing teeth. 

(1) The very active evolutionary process which is going on within the 
jaws at the period of the eruption of the teeth calls for a much larger 
volume of blood within the parts than is normal at a later period in life. 
The illustrations shown in Figs. 213 and 214, made from the jaw of an 
embryo cat, show what a considerable amount of space is occupied in the 
jaws at this period of dental evolution by the follicles of the teeth. This, 
under certain conditions which have already been mentioned, often pro- 
duces over-stimulation of the parts, followed by congestion, which may 
induce reflex nervous phenomena, or through the sympathetic nervous 

5 



66 



OPEEATIVE DENTISTRY 



Fig. 215. 




system establish morbid conditions of the stomach, the bowels, the respira- 
tory tract, the skin, etc. 

(2) The lateral pressure induced within the jaws by the contempora- 
neous evolution of two sets of teeth must be very considerable at this pe- 
riod. If the jaws of a child six months old are examined it will be noticed 
that the permanent teeth in various stages of development are so crowded 

together that their crypts overlap each 
other, but each apparently is striving to 
obtain a normal position. As the growth 
and enlargement of the jaws takes place 
they gradually assume their proper posi- 
tions within the arch, ready to advance 
as soon as the way is made clear for them 
by the lengthening of the jaws and the 
exuviation of the deciduous teeth (Fig. 
215). 

(3) The peripheral irritation of the 
gingival nerves from the pressure of the 
advancing teeth is often under- estimated, 
as any individual will readily admit who 

First and second dentition, upper and lower ]iag Suffered from the eruption of a 

troublesome third molar. 

In viewing the subject of dental irritation from this stand-point the 
wonder would seem to be that morbid phenomena are not more often 
manifested than they are during the eruption of the deciduous teeth. 

Symptoms. — The symptoms of dental irritation may be classified 
under two heads, — viz., constitutional and local. 

The constitutional symptoms which may be manifested as complications 
during the period of first dentition are fever, diarrhoea, vomiting, cough, 
bronchitis, various eruptions of the skin, occasionally swelling and suppura- 
tion of the lymphatic glands, and nervous phenomena like spasms of the facial 
muscles, ' ' which send doting mothers into ecstasy over the heavenly smile 
of the sleeping infant," strabismus, chorea, convulsions, and meningitis. 

Pyrexia, or fever, is perhaps the most common constitutional symptom 
or complication of morbid primary dentition. The character of the fever 
may be mild or intense, according to the degree of susceptibility of the 
child to nervous irritation, and there is a marked difference in children in 
this respect. In one child the elevation of temperature may be slight, not 
going above 100° F., while in another, with apparently no greater cause 
for an abnormal rise in temperature, it may reach 103° or 104° F. , and be 
accompanied with gastric or intestinal disturbances or convulsions. 

The fever of dentition, which is irritative in character, is peculiar in 
that it is very irregular in its manifestations. It is often higher in the 
morning than in the evening, reversing the usual order, and it varies con- 
siderably from day to day. A high morning temperature often follows a 
restless night, and a low evening temperature follows a quiet day. Great 
vigilance should characterize the care of children when suffering from the 
irritative fever of dentition. A feverish child is very susceptible to sudden 



ERUPTION OF THE TEETH. 67 

changes of the weather from a dry to a damp atmosphere, from a warm to 
a cold room, or to cold draughts, and to improper feeding. Too much 
emphasis cannot be placed upon the importance of properly protecting the 
child against these contingencies. Catarrhal attacks at this period are far 
more likely to be the result of exposure which has induced a chill, or to 
improper feeding, than to mechanical irritation of the gingival nerves by 
an erupting tooth. 

Diarrhoea is another very common complication of morbid dentition, 
but dental irritation is by no means the most common cause of diarrhoea. 
Catarrhal conditions of the stomach and bowels are very prevalent at this 
period ; but in the opinion of the writer these conditions are more often 
the result of bad sanitary and hygienic surroundings, exposure to cold, or 
improper feeding and unwholesome food than to any other cause or causes. 

Diarrhoea and vomiting are most prevalent during the hot months of 
the year, when the changes in the weather are often the greatest and the 
clothing of the child least likely to afford the proper protection against a 
sudden fall in the temperature. The food also is more liable to be ren- 
dered unwholesome by fermentative changes during the hot weather than 
at any other time. A chill or a cup of milk partially changed by lactic 
acid fermentation, or the inrpure, chemically preserved stuff often sold in 
our large cities as pure milk, are responsible for a large majority of the 
cases of gastric and intestinal disturbances and nervous phenomena. 

Parents and nurses through ignorance or carelessness often feed little 
children with foods that their stomachs, at this early age, are incapable of 
digesting ; for instance, meats, hard-boiled eggs, beans, cabbage, bananas, 
apples, cherries, and many other similar things ; and then, if the child's 
stomach refuses afterwards to retain food, or it suffers from diarrhoea or 
cholera infantum or convulsions, and as a result gives up its puny life, the 
illness or the death is often charged to teething. 

Bronchitis is usually attributed to ordinary exposure, and yet it some- 
times occurs in children in whom every precaution has been taken to pre- 
vent chilling the surface of the body ; under such circumstances it may be 
the result of dental irritation. 

Cutaneous eruptions frequently occur during primary dentition, such as 
urticaria, eczema, impetigo, lichen, prurigo, and herpes zoster, which are 
often the expression of reflex nervous irritations. 

Reflex nervous phenomena, associated with morbid dentition, are of the 
most varied character, both as to degree and the peculiarities of their 
manifestations. These manifestations are often difficult to understand, 
and still more difficult to trace to their origin. Pepper says, in explana- 
tion, "Doubtless the extensive ramifications of the great vagus nerve and 
its connections, both of origin and distribution, with the exquisitely sen- 
sitive fifth nerve, as well as with the facial nerve, and with the sympa- 
thetic system, will explain why the irritation should now be seated in the 
gastro- intestinal tract, giving rise to vomiting and diarrhoea ; now in the 
respiratory tract, provoking cough more or less severe, or even a well- 
marked bronchitis ; now manifests itself in various cutaneous eruptions ; 
now accumulates in the cerebro-spinal axis, manifesting its presence by 



68 OPERATIVE DENTISTRY, 

slight spasms, or discharging with terrific force in some of those convul- 
sive seizures which are the dread of mothers and the cause of much anxiety 
to physicians." 

The second summer is generally considered as the most critical period in 
the life of the infant, the popular notion being that the dangers and com- 
plications which arise are largely due to the eruption of the cuspid and 
molar teeth, as one or the other of these groups usually makes its appear- 
ance at about this time. There is really no reason why a cuspid or molar 
tooth should cause a greater degree of irritation than an incisor ; while, 
upon the other hand, in a normal child, with the increase in the age and 
strength, there usually comes greater resistive power to such forms of irri- 
tation ; consequently the second summer should be less dangerous than the 
first so far as dentition is concerned. 

The dangers associated with the second summer do not in any great 
measure depend upon dental irritation, but rather upon improper feeding. 
Children of this age are prone to devour anything that may be given to 
them, or upon which they can lay their hands, and unless they are care- 
fully watched and strict supervision instituted over their food, as to its 
kind, quality, and quantity, many illnesses are likely to occur ; and if a 
group of teeth — the cuspids or molars — should be erupting when the 
illness supervened, the chances are that they would be considered the 
primary cause of the derangement rather than the ingestion of indiges- 
tible substances or foods in which fermentative processes had already been 
established. When these conditions are complicated with the debility con- 
sequent upon previous disease or a period of intense heat, the results often 
prove fatal. 

A very large percentage of all the children born die before they reach 
the end of the fifth year as a result of the diseases and accidents peculiar 
to this period of life. Arbuthnot calculates that one in every ten children 
dies from the effects of the associative and influenced lesions of the age. 
(Garretson.) The mortality among hand-fed children is much greater than 
this. Camper is the authority for the statement that out of five thousand 
nine hundred and eighty-nine children admitted to foundling hospitals, 
only eight hundred and eighty-four were found living at the end of the 
fifth year (Garretson), or 85.239 per cent, had died. 

Eouth says, in this connection, ' ' In England, out of one hundred chil- 
dren born and fed by hand, 15.2 per cent, will die the first month, 1.7 the 
second, and so on. In France, out of one million births, 20,121 die in the 
first week, 22,128 in the second, and 22,236 in the sixteen days following." 

According to the English Life Table, ' ' the annual rate of mortality 
among infants per thousand is equal to 571.3 in the first month of life, de- 
clining, however, to 91.6 per thousand in the eleventh month. The 
annual rate among infants aged one month and under one year does not 
exceed 114.6 per thousand, whereas among infants from birth to one year 
of age it is equal to 165.6 per thousand. 

" Among infants of six months the mortality is but one-fifth of the 
rate which prevails during the first month of life." (British Medical Jour- 
nal, vol. i., 1875, p. 785.) 



ERUPTION OF THE TEETH. 



69 



The report of the Register-General of England for 1897 shows that "under 
the most favorable circumstances the mortality of infants under one year 
of age is very high. Reference to several life tables shows that the same 
rate of death is not again experienced until the age of about eighty years. 
But the mortality in the first year of life is by no means evenly spread 
over that year ; about one-half of it occurs in the first three months. The 
following table shows the survivors at three months, six months, and 
twelve months out of one hundred thousand of each sex born in 1881-90 ; 
the deaths in the intervals are likewise shown.' 7 



England and Wales. 


England and Wales. 


Born and Surviving at Each Age. 


Dying in Each Interval of Age. 


Born 

Three months . . 


Males. 


100,000 
93,791 

88,895 
83,896 

100,000 
93,791 
91,138 

86,887 


Males. 
Between birth and three months... 
Between three and six months .... 
Between six and twelve months. . . 

Females. 
Between birth and three months. . . 
Between three and six months .... 
Between six and twelve months. . . 


.. 7880 
.. 3225 
.. 4999 


Twelve months.. 
Born 


Females. 


.. 6209 
. 2653 






. 4251 


Twelve months . 







The rate of mortality among infants of both sexes under the age of twelve 
months was equal to 142 per thousand births registered as compared with 
149 per thousand in the preceding decennium. In 1881-90 the infantile 
rate among males was equal to 155 per thousand births, and among females 
to 128 per thousand, the rates in 1871-80 having been 163 and 134 re- 
spectively. 

Local Symptoms. — The local symptoms which usually accompany 
first dentition are as follows : Salivation is the first indication of ap- 
proaching dentition. From birth to the fourth or fifth month the sali- 
vary glands seem to remain nearly or quite inactive, but as the time ap- 
proaches for the teeth to begin the process of eruption the salivary glands 
take on a marked activity, the flow of the secretion being so abundant as to 
cause it to dribble from the corners of the mouth and to wet the garments 
about the neck and chest. This wetting of the clothing is often respon- 
sible for the catarrhal attacks associated with dentition, while the swal- 
lowing of large quantities of saliva has been thought in some cases to be 
responsible (Pepper) for the diarrhoea by reason of its saline constituents, 
which may act as a mild cathartic. 

Swelling or tumefaction of the gums is next observed, at about the 
sixth to the seventh month, in those locations where the teeth are about to 
be erupted. Sometimes the gums become congested, tense, glistening, hot, 
and painful ; at times tender to the touch, but generally the painful sensa- 
tions are relieved by pressure, hence the desire of the child to bite upon 
hard substances. 



70 OPERATIVE DENTISTRY. 

Accompanying these local symptoms there is often a slight elevation 
of temperature with flushing of one or both cheeks, irritability of temper, 
peevishness, and restlessness during sleep, with rolling of the head from 
side to side. Occasionally the child sleeps with the eyelids only half 
closed or the eyes rolled upward. Otalgia is not an uncommon occur- 
rence, as may be inferred from the child poking its fingers into the ex- 
ternal meatus or pressing its ear into the pillow or against the bosom of 
the nurse. In the ordinary cases of dentition these may be the only mani- 
festations. In the more severe cases one or more of the constitutional 
symptoms above described may be present as complications. 

Occasionally there exists a disposition to the formation of aphthous 
patches, ulcerous stomatitis, within the mouth, upon the lips, cheeks, gums, 
and tongue, most frequently, however, at the commissure of the lips, upon 
the buccal surface of the alveolar ridge, and the tip of the tongue ; the 
latter being due, in all probability, to the friction of the sharp and ser- 
rated edges of the incisor teeth. 

Sometimes in children suffering from debility the aphthous patches be- 
come confluent, forming large ulcerated surfaces ; or the gums over the 
advancing teeth become ulcerated, exceedingly tender and painful, — odon- 
titis infantum, — or gangrenous, forming large, foul-smelling sloughs, — gan- 
grena oris, — which expose the teeth and the bone. Both of these conditions 
are difficult to cure, the latter often taking on the more severe and fatal 
form of gangrenous ulceration known as noma. 

A more common but less severe form of stomatitis, in which there is a 
general inflammatory condition affecting the mucous membrane, and espe- 
cially the mucous follicles of the tongue and cheeks, — catarrhal stomatitis, — 
accompanied by swelling of the submaxillary glands and infiltration of the 
surrounding connective tissue, is frequently seen in the children of the very 
poor, and is usually associated with bad or insufficient food and unsanitary 
surroundings. 

Constitutional Treatment. — The treatment of morbid dentition with 
its constitutional and local complications generally falls to the lot of the 
family physician, and the dental surgeon or stomatologist is rarely con- 
sulted except in the more severe cases involving serious oral lesions or re- 
flex phenomena dependent upon oral conditions. It will not be necessary, 
therefore, to dwell at length upon the treatment of the various general 
morbid conditions which accompany difficult dentition, as these belong to 
the realm of general medicine, and those especially interested in this part 
of the subject can refer to works devoted to this department of medical 
science. It will be sufficient to say, then, that the constitutional symp- 
toms are to be treated upon general principles, the^rs^ of which is to ascer- 
tain the cause, second, to remove it if possible, and third, to assist nature in 
re-establishing a normal condition. It will not be amiss, however, to quote 
a few lines from Day ("Diseases of Children") upon this part of the subject. 
He says, " The treatment of dentition will depend upon the general symp- 
toms that are present and the constitution of the patient. The practi- 
tioner must exercise his own judgment as to the treatment to be adopted, 
and not blindly attach himself to any routine plan. The strong and vig- 



ERUPTION OF THE TEETH. 71 

orous child who is feverish and thirsty, with a hot and tender guru, a full 
pulse, and constipated bowels, will demand quite a different mode of man- 
agement from a puny and rickety child whose teeth are delayed. In 
strong children a grain of calomel with two or three grains of rhubarb 
will be required to clear the bowels. A saline mixture, as the citrate of 
potash, should be given to abate the pyrexia, and if the child is excited 
and sleepless, a few drops of tincture of henbane may be added, or a 
draught at bedtime containing hydrate of chloral and bromide of potas- 
sium should be given. The child's head should be kept cool, and what- 
ever determines to cerebral congestion should, if possible, be prevented. 

"In rickety children a mild aperient is occasionally required, such as 
bicarbonate of soda and rhubarb, to regulate the bowels and to correct the 
secretions. A teaspoonful of castor oil may be advisable now and then, 
and if the bowels are overactive, a grain of Dover's powder at bedtime is 
often of great service. If there is vomiting and flatulence, some carmina- 
tive will be necessary. In cases where there is much restlessness and dis- 
turbance of the nervous system, bromide and iodide of potassium with sal 
volatile will often abate sickness and relieve head-symptoms if present." 

Local Treatment. — In those cases in which the gums are considerably 
congested and swollen, causing pain on pressure, and accompanied with gen- 
eral febrile symptoms, vomiting, diarrhoea, or cough, almost immediate 
relief is often obtained by the free use of the gum-lancet. To be effective 
the lancet must reach the tooth. The incision for the six anterior teeth of 
each jaw should follow the line of the morsal or the cutting edge of each 
tooth, except in the cuspids when the cusp has penetrated the gum (Fig. 
216), when the incision may be made as shown in Fig. 217, while for the 

Fig. 216. Fig. 217. Fig. 218. Fig. 219. Fig. 220. 




molars crucial incisions should be made, one from the disto-lingnal cusp 
to the mesio-buccal, the other from the disto-buccal cusp to the mesio- 
lingual (Fig. 218.) 

These incisions follow the line of the cutting edge in the six anterior 
teeth, and cut directly across the cusps of the molar teeth which are nearest 
the surface of the gum (Fig. 219), and for that reason are to be preferred 
to those which are made upon the lines of the sulci between the cusps, as 
shown in Fig. 220. 

The indiscriminate use of the gum-lancet, however, should be depre- 
cated. Much harm has often been done by a thoughtless or empirical use 
of this valuable means of treatment, while, upon the other hand, many 
lives have been saved by an intelligent use of it. 

Many writers and physicians of experience have claimed that its use is 
never indicated, and when used it is productive of more harm than good. 



72 



OPERATIVE DENTISTRY. 



The same has been said of blood-letting in pneumonia, and yet, in certain 
cases, there is not a more valuable means of treatment known to medicine 
than this once much-abused and now often- maligned procedure. The dif- 
ficulty and danger in both of these methods of treatment do not lie in the 
methods, but in the discriminating power of the person who employs them. 

If the gum-lancet is applied before the tooth has advanced from its 
crypt, the incision will necessarily be deep, and the end sought for — viz., 
the extrusion of the tooth through the gum — will not be realized ; conse- 
quently the lips of the incision will unite again ; and if this procedure is 
repeated, and it frequently is, a mass of cicatricial tissue is formed that is 
likely in a frail and debilitated child to become the seat of ulceration 
when the tooth shall finally make its appearance through the gum. Such 
an indiscreet use of the gum-lancet cannot be too strongly condemned, for 
the irritation certainly does not come from pressure 'upon the gingival 
nerves until the tooth advances from its crypt. 

Dental irritation which does not produce local symptoms within the 
mouth — swelling or congestion of the gum, or both — is not due to pressure 
upon the gingival nerves, but rather to one or both of the other causes of 
dental irritation before mentioned. 

The operation of lancing the gums is best performed with the assistance of 

a nurse. In operating upon the lower jaw the child should be seated in 

the lap of the operator, with its head against his breast, the 

Ftp 2?1 

hands and feet being controlled by the nurse. The left thumb 
of the operator is placed in the mouth of the child upon the 
tongue, the index-finger between the alveolar ridge and the 
lower lip, with the remaining fingers under the chin. In this 
way the head can be firmly held, the tongue controlled, and the 
lip held out of the way ; it also gives a good view of the inferior 
alveolar arch, and permits the operator to reach any part of it 
with the lancet. The best form of gum-lancet is shown in Fig. 
221, which is a flat blade turned at right angles to the shaft, 
and having a sharp, rounded edge. 

In operating upon the upper jaw the child should be laid 
upon its back in the lap of the nurse, with its legs passing under 
her arms, while the arms of the child are held firmly to its 
sides. The head should be held between the knees of the oper- 
ator. One or more fingers of the left hand of the operator are 
then inserted within the mouth of the child, and the alveolar 
ridge grasped with the thumb and index-finger. The gum- 
lancet should be held in the right hand as a pen or pencil is held, and 
the hand should be steadied by resting the ring-finger and the little finger 
upon some convenient portion of the face while the incisions are being 
made. 

Sometimes it becomes necessary in the eruption of the molar teeth to 
remove the band of overlying gum-tissue which remains after the cusps 
have pierced the gum, as it seems to retard the extrusion of the tooth. 
This can be best accomplished by a pair of sharp-pointed curved scissors 
(Fig. 222). 



Gum-lancet. 



ERUPTION OF THE TEETH, 



73 



Troublesome hemorrhage occasionally follows lancing of the gums, but, 
as a rule, the bleeding is so slight as not to need any especial attention. 

In troublesome hemorrhage the bleeding gums may be bathed with a 
strong solution of alum, or touched with an alum pencil, or tannic acid 
in glycerol may be applied upon a piece of gauze or absorbent cotton. In 
obstinate cases a compress applied to the bleeding part, and the jaws closed 
upon it and held in that position by a bandage passed under the chin and 
over the head, will usually control it. 

The application of Monsel's solution or the nitrate of silver is recom- 
mended by several authorities, but this is rather dangerous practice, from 

Fig. 222. 




the fact that they cause sloughing of the surface of the gum-tissue ; this is 
often followed by secondary hemorrhage, which is sometimes more trouble- 
some to control than the primary bleeding. 

As a constitutional remedy, tincture of ergot in one- to five-drop doses 
in a little water, repeated every ten minutes until bleeding ceases, or until 
twenty to thirty drops have been administered, will usually prove effective. 



EXUVIATION OR SHEDDING- OP THE DECIDUOUS TEETH. 

Definition. — The exuviation of the deciduous teeth is a peculiar 
physiologic process, whereby the roots of the teeth are gradually dis- 
solved — organic and inorganic material — and their elements removed by 
resorption. 

It may truthfully be said that the process of the evolution of the 
temporary teeth is hardly completed before preparations are made for a 
retrograde change which shall result in the tearing down of these struc- 
tures, which have been so carefully and elaborately built, to make room 
for those larger and more permanent organs which are intended to serve 
the body to the end of life. 

The process of exuviation begins in the central incisors in about a year, 
or a little more, after the complete formation of their roots, — viz., in the 
middle or latter part of the third year,— but it is not completed until about 
the seventh year, when their crowns fall out from lack of support. The 
lateral incisors are attacked a few months later than the centrals, and are 
shed at seven and one-half to eight years of age. The process begins in 
the first molars at the age of six and one-half to seven years, terminating 



74 OPERATIVE DENTISTRY. 

in the exuviation of their crowns at about the tenth year. The second 
molars are attacked from six months to a year later, and the process is 
completed at about the eleventh year. The cuspids are usually the last of 
the deciduous teeth to be exuviated, although many instances will be ob- 
served in which they are shed before the second molars. The process 
begins in these teeth at about the eighth year, and is not completed until 
the twelfth year, or even later. 

Individual teeth are often retained in the jaws much beyond the usual 
time for their exuviation. 

These deviations from the normal order may be due to : 

1. Tardy development of the permanent tooth which should replace it. 

2. Non-development of the tooth which should replace it. 

3. Malposition of the tooth of replacement, resulting in its eruption 
internal or external to the alveolar arch, or in some distant location. 

4. Malposition of the permanent tooth, which makes it impossible for it 
to erupt. 

5. Death of the pulp of the deciduous tooth from caries or traumatism. 
Process of Resorption. — The elder Tomes was the first to accurately 

study the j)rocess of resorption of the deciduous teeth, and our present 
knowledge of the subject is largely based upon these investigations. If 
an incisor tooth is extracted at about the fourth year, pits or small exca- 
vations will be found at the apex or upon the sides of the root. Usually 
only one such excavation will be found, and that generally upon the 
side of the root nearest to the advancing permanent tooth. It is not an 
uncommon occurrence, however, to find one or more of these excavations 
in locations which are remote from the successional tooth, in fact, upon 
the opposite side or even well towards the cervix. These excavations 
progressively enlarge and deepen until, finally, the whole of the root is 
dissolved. 

The process usually begins in the cementum, progresses to the dentin, 
and may finally attack the enamel. 

The writer recently removed a second deciduous lower molar in which 
the dentin had been entirely removed from the crown and a considerable 
portion of the inner surface of the enamel had been dissolved. He also 
has in his collection the crown of a replanted third lower molar, dissolved 
in the same manner, which had been rejolanted three years before. (The 
tooth had been affected with pyorrhoea alveolaris ; treatment by extracting, 
scraping the root, replanting, and banding it to another tooth was done 
as an experiment.) In this case the dentin has all been removed from the 
crown except a thin lamina in the centre, which is very much u honey- 
combed." In the first instance the process is physiologic, in the other 
pathologic, yet the results were identically the same. 

Tomes says, "That part of the dentin which immediately surrounds 
the pulp — in the deciduous teeth — appears to have more power of re- 
sistance than any other part of the tooth, and thus often persists for 
a time as a sort of hollow column." The pulp retains its vitality to 
the last, and seems to be necessary to the completion of the resorptive 
process. 



ERUPTION OF THE TEETH. 75 

The alveolar walls immediately surrounding the roots of the deciduous 
teeth are also removed by the same resorptive process, and new alveoli are 
formed about the roots of the permanent teeth as they come into place. 

Fig. 223 illustrates a peculiar case of exuviation of a tooth in the jaw 
of a kitten, from the private collection of Dr. Vida Latham. The tooth 
was either formed without a root, which is most probable, or the root has 
been removed by resorption, and the base of the pulp canal filled with 
secondary dentin. The permanent tooth lies beneath in its bony crypt. 

The resorptive process seems to be dependent upon some form of vital 
chemic change taking place at various portions of the surface of the root, 
which induces a molecular dissolution of the tooth-structures and the sur- 
rounding bone, and the resolved elements are returned to the general 
circulation by the absorbent and lymphatic vessels. 

The agencies which set this process in operation and the modus ope- 
randi by which the process is accomplished are still subjects of discussion. 

The view formerly taught in reference to the cause of the resorption 
of the deciduous teeth was that it was induced by the pressure of the 
advancing permanent teeth. 

Various objections can be maintained in opposition to this view. For 
instance, in some of the lower animals, and particularly in snakes and 
certain fishes, conditions exist during the evolution of successive sets of 
teeth that prove conclusively that resorption takes place similar to that in 
man, and entirely independent of pressure. " In the frog and the crocodile 
the growing tooth-sac passes bodily into the excavation made for it in the 
base of the tooth, which has preceded it, while if pressure had any share 
in the matter, the cells of its enamel-organ must have inevitably been 
crushed and destroyed." (Tomes.) 

In the snake, whose succession of teeth are endless, the new teeth are 
develoj>ed at the inner side of those already in position, and when a tooth 
is about to be shed the process of resorption attacks the bone at its base, 
removing the inner side before the outer side is at all affected. 

The new tooth gradually moves forward and occupies the position 
made vacant by the resorption and exuviation of the preceding one. But 
at no time during this process do the exuviating and the new teeth come 
in contact with each other. 

Again, instances are numerous in which it can be shown that the 
resorptive process frequently begins, as already mentioned, at jjoints 
remote from the surface of the advancing permanent tooth, where pressure 
from this cause could not possibly occur. 

Another reason for doubting the correctness of this view is the fact 
that frequently the permanent teeth are still enclosed in their bony crypts 
at the commencement of the process of resorption, and the process is not 
infrequently completed and the tooth exuviated before the permanent 
tooth is ready to leave its follicle. 

The presence even of the permanent tooth is not necessary to establish 
the resorption of the root of the deciduous tooth, ' ' for it has been success- 
fully accomplished in the absence of its successor." (Pierce.) 

Mechanical pressure, however, is capable of producing resorption of 



76 OPERATIVE DENTISTRY. 

tissue, instances of which are common in the practice of orthodontia. 
In moving a tooth from an abnormal to a normal position the orthodontist 
depends upon his power to produce resorption of the alveolar process by 
applying mechanical pressure in a certain direction. 

Eesorption of bone is often brought about by the pressure of an en- 
larging aneurism or of the accumulations of fluid or of pus, as, for in- 
stance, in the maxillary sinus, where it sometimes results in the rupture 
of one of the walls of the sinus. 

The active agent, apparently, which produces the resorption of the 
roots of the deciduous teeth is a soft, highly vascular papilla, — the " ab- 
sorbent organ," — which is found in close contact with the root of the tooth. 

The surface of the papilla is composed of very large multiform cells, — 
giant cells, — each cell being composed of several smaller ones, the number 
varying from two or three to twelve or fifteen. The prevailing forms of 
the cells are ovoid and spherical, although some of them have the appear- 
ance of the myeloid cells of Kolliker (Fig. 224). The excavated surface of 
the tooth lying next to the absorbent organ, if examined microscopically, 
is seen to be covered with numerous very small cup-shaped indentations, — 
the lacunae of Howship, — in which a giant cell has evidently been lodged. 

The modus operandi by which these giant cells affect a dissolution of the 
dental tissues is not definitely known. Giant cells, however, are always 
present wherever the resorption of hard tissues like bone is going on, or 
foreign substances located in the body that are capable of being dissolved. 
The giant cells which compose the "absorbent organ" are no doubt modi- 
fied osteoclasts derived from the pericemental membrane of the decidu- 
ous teeth, and perform the same office for the teeth that the osteoclasts do 
for the bone, and are known as "odontoclasts." 

Several theories have been advanced in explanation of the process of 
resorption of the deciduous teeth. 

It was thought, until quite a recent period, to be due to the formation or 
secretion of an acid by the "absorbent organ," which attacked the dental 
tissues and dissolved them, and that these elements were then removed by 
the absorbents and carried into the general circulation. 

Abbott advanced the theory that the absorbent organ was not the active 
agent in the resorption of the temporary teeth, but rather the result of it. 
The process of resorption, he believed, was brought about through the 
living matter, the organic basis substance of the dental tissues, by a retro- 
grade metamorphosis, or a change to embryonal tissue, and that the 
process is closely allied to that of inflammation. That the lime-salts are 
first dissolved and the basis substance or organic material is afterwards 
liquefied. Medullary elements then arise out of the liquefied material and 
proliferate, resulting in a new formation of medullary tissue, the so-called 
" absorbent organ." 

Black has suggested the most rational explanation of the process, one 
which is in entire harmony with the latest developments in physiology, — 
namely, that the absorbent organ secretes or elaborates a digestive fluid 
or soluble ferment which dissolves or digests the dental tissues and alveolar 
walls, and prepares them to be resorbed, just as under certain circumstances 



' 




r X 



Pig. 223. — Vertical section of a peculiar case of exuviation of a tooth in the jaw of a kitten. X "5. 




Fig. 224.— Absorbent organ and portion of dentin in situ. A, giant cells. ( V. A. Latham.) X 05. 



ERUPTION OF THE TEETH. 77 

bone is resorbed, or ivory pegs which have been driven into the tissues, or 
catgut sutures, silk ligatures, decalcified chicken-bone, drainage-tubes, or 
even sponges are dissolved and removed by the process of resorption. 

Devitalized temporary teeth are not resorbed ; hence it would seem 
that the vital pulp must play an important part in the resorptive process. 
Pierce says the very moment vitality of the pulp ceases that instant this 
retrograde metamorphosis, designated "physiologic absorption," termi- 
nates. 

Vital permanent teeth sometimes undergo a process of resorption at 
various points upon the surface of their roots as a result of pericemental 
irritation or inflammation, and after the subsidence of the morbid condi- 
tion new bone or cement formation takes place at those points by the cal- 
cification of the absorbent cells. 

Tomes says, i l The process of absorption once commenced does not 
necessarily proceed without intermission, but may give place for a time to 
actual deposition of osseous tissue on the very eroded surface ; probably 
by the agency of the absorbent cells themselves, which are capable of 
being calcified in the excavations they have individually made." 

Replanted, transplanted, and implanted teeth are often attacked by a 
process of resorption which in many respects is quite similar to the re- 
sorptive process which removes the roots of the deciduous teeth. This 
difference, however, is to be noted, that while in the deciduous teeth and 
vital permanent teeth the process leaves a comparatively smooth exca- 
vation, in devitalized teeth the cementum and dentin become more or 
less roughened and honeycombed. The latter process is also attended with 
considerable soreness, due to the pericemental inflammation, and pus not 
infrequently forms, which may escape around the cervix of the tooth or 
point through the gum, while in the process as seen in the exuviation of 
the deciduous teeth no inflammatory symptoms are present. 

The former is a pathologic process established to remove an organ which 
has become a source of irritation and acts as a foreign body. The latter 
is a physiologic process established to remove an organ which has served 
the purpose of its creation, but which is to gradually give place to a 
stronger and more enduring counterpart of itself. Pathology, we are 
taught to believe, is perverted physiology ; but just where normal func- 
tion ceases and morbid conditions begin science has not as yet been able 
to demonstrate. The accompanying diagram (Fig. 225, page 78), drawn 
by Professor C. N". Peirce, most admirably illustrates the periods at which 
calcification takes place in the deciduous and the permanent teeth, and 
also the decalcification or resorption of the roots of the deciduous teeth. 

ERUPTION OF THE PERMANENT TEETH. 

Normal secondary or permanent dentition begins at about the sixth year 
by the eruption of the first molars, which take position directly behind 
the second deciduous molars, the growth of the jaws having made this 
possible by increasing the distance between the second deciduous molar 
and the ascending ramus in the lower jaw, and between the same tooth and 
the tuberosity in the upper jaw. 



78 



OPERATIVE DENTISTRY 




lO >* M MH 



ERUPTION OF THE TEETH. 79 

The growth of the jaws, which keeps pace with the eruption of the per- 
manent teeth, is mainly confined to an elongation of the horizontal ramus 
between the second deciduous molar and the angle. There is, however, a 
certain amount of growth taking place at the symphysis menti and at the 
median and intermaxillary sutures, and also in the interstitial substance 
of the jaws. 

This statement is corroborated by the fact that as the period of second 
dentition approaches, spaces appear between the deciduous teeth which 
gradually widen until the primary teeth are exuviated. The widest space 
in the lower jaw is between the central incisors, while in the upper jaw it 
is between the central incisors and between the lateral incisors and cus- 
pids. Nature thus beautifully provides for the increase in the number 
and of the size of the succeeding teeth by arranging the growth of the 
jaws in harmony with the space required for a normal arrangement of the 
individual permanent dental organs. 

There is often a considerable variation in the time and order of the 
eruption of the permanent teeth, even in healthy individuals, but the fol- 
lowing table gives approximately the date and the order in which they 
may be expected to appear in the dental arch : 

First molars 5 to 7 years of age. 

Central incisors 6}- to 8 years of age. 

Lateral incisors 7 to 9 years of age. 

First bicuspids 9 to 11 years of age. 

Second bicuspids 10 to 12 years of age. 

Cuspids 11 to 14 years of age. 

Second molars 11 J to 13 years of age. 

Third molars 16 to 21 years of age, 

or at any period later. 

The third molars not infrequently fail to appear at all. They are usu- 
ally developed, but remain in the jaws for lack of space in the arch to 
accommodate them, or are so mal posed that their eruption is difficult or 
impossible. 

Symptoms. — The symptoms which accompany second dentition are 
usually so mild as not to attract special attention. There is slight saliva- 
tion and a little tenderness of the gums over the erupting teeth. Occasion- 
ally, however, marked symptoms may be present, profuse salivation, great 
tenderness and tumefactiou of the gums, sometimes accompanied with ul- 
cerative stomatitis, neuralgia of the trifacial nerves, and epileptic seizures. 

The eruption of the third molars, particularly the inferior ones, is often 
productive of great suffering from inflammation of the gums and surround- 
ing tissues. Suppuration not infrequently supervenes, which may extend 
to the jaw, causing large abscesses and infection of the lymphatic glands. 
Abscesses of this character in the lower jaw often burrow downward into 
the tissues of the neck, involving the important vessels of this region, the 
accumulation of pus being sometimes very considerable. The writer once 
opened such an abscess from which more than a pint of pus was extracted, 
and has frequently in his hospital practice treated cases in which half that 
quantity has been withdrawn from the abscess. 



80 OPERATIVE DENTISTRY. 

Septicaemia and necrosis of the jaw sometimes complicate the affection. 
The presence of septicaemia adds greatly to the dangers surrounding the 
case, and may cause a fatal termination. 

Necrosis of the jaw may be of slight or considerable extent. It may 
involve only a jDortion of the alveolar process or extend to the body of the 
bone, destroying large portions of it, or even the entire half of the jaw. 

The process of eruption of the permanent teeth is so nearly analogous to 
that of the temporary dentition that no special description seems necessary. 

Irregularities in the Position of the Permanent Teeth. — In the 
eruption of the succedaneous teeth — those which succeed the deciduous set — 
rapid resorption of bone takes place upon the labial and buccal aspects of 
their crypts, resulting in an opening very much larger than the crown of 
the tooth. The fact will therefore be recognized that any slight mechanical 
obstruction situated in the path of its progression would be sufficient to 
deflect it from its normal course and result in an irregularity in position. 
The muscular action of the lips and tongue, the habits of tongue-sucking 
and thumb- sucking, are all potent factors in modifying the arrangement of 
the teeth when applied at this period of their evolution. Certain develop- 
mental conditions of the bones of the face are very common causes of irreg- 
ular arrangement of the permanent teeth, and by some authorities thought 
to be the most prolific causes, — namely, excessive development and ar- 
rested or retarded development of the maxillary bones. These conditions 
may be the result of many and varied causes, some hereditary, others ac- 
quired. These may again be divided into constitutional and local. 

Among the constitutional conditions which may be classed as direct 
inherited causes are, first, constitutional taints, like syphilis, tuberculosis, 
and neurotic conditions, peculiarities in the formation of the jaws and of 
the teeth, peculiarities in the arrangement of the teeth in the arch, and 
tendencies to the suppression of certain teeth, or to the presence of super- 
numerary teeth ; second, conditions which may be classed as indirect in- 
herited causes, as, for instance, when one peculiarity is inherited from the 
father and another from the mother, which combined form an irregularity, 
like the inheritance of large teeth from one parent and a small jaw from 
the other. The deformity is not directly inherited from either parent, but 
indirectly from both. 

Miscegenation of nations and distinct races is often a prolific source 
of malformations of the jaws and of irregularities of the teeth, which oper- 
ates by mixing national and race peculiarities which are more or less 
antagonistic to each other. Third, acquired constitutional defects. These 
result from diseases or traumatisms which interfere with nutrition, and thus 
prevent a normal development of the maxillary bones and the teeth, or 
cause an abnormal arrangement of the teeth in the alveolar arches. 

The local conditions which may act as factors in producing an abnormal 
arrangement of the teeth are : 

1. Undue retention of the deciduous teeth or parts of a tooth. 

2. The presence of supernumerary teeth. 

3. The too early extraction of the deciduous teeth. 

4. Injudicious extraction of permanent teeth. 



ERUPTION OF THE TEETH. 81 

5. Delayed eruption of a permanent tooth. 

6. Mouth-breathing due to enlarged tonsils and adenoid growths in the 
nasopharynx. 

7. The habits of tongue-sucking and thumb-sucking. 

The retention of a deciduous tooth beyond the normal period of its exuviation 
is often productive of a malposition of the succeeding teeth. Nature pro- 
vides for the resorption of the roots of deciduous teeth. Death of the 
pulp prevents physiologic resorption, therefore the unabsorbed root of 
the retarded tooth may cause the permanent tooth to be deflected from the 
normal position. 

The presence of a supernumerary tooth may also operate in a like manner 
to deflect the permanent tooth from a proper position in the arch, or so 
crowd the arch by its presence as to destroy the occlusion. 

The too early extraction of the deciduous teeth tends to retard the inter- 
stitial growth of the jaw ; permits the teeth upon either side of the space 
made by the extraction of the deciduous tooth to move or tilt towards each 
other, thus robbing the permanent tooth of its required space, and forcing 
it into an abnormal position, while the extraction of the second deciduous 
molar before the first permanent molar is erupted permits this tooth when 
erupted to move forward and occupy the space needed by the second 
bicuspid. This procedure also induces, as graphically shown by Talbot, 
a shortening of the arch of the jaw upon that side, thus crowding the 
cuspid and bicuspids out of line, and causing a deformity difficult to 
remedy except by the extraction of one of the bicuspids. 

The injudicious extraction of permanent teeth often entails a serious incon- 
venience to the individual by permitting a tilting of the crowns of the 
proximate teeth and forming large inverted V-shaped spaces which are 
difficult to cleanse, and therefore invite caries. This condition frequently 
follows the extraction of the first permanent molar if delayed until after 
the eruption of the second molar. 

The extraction of the permanent superior lateral incisors, to make room 
for prominent cuspids, also causes a deformity in the arrangement of the 
teeth which cannot, except in rare instances, be corrected, and should be 
condemned in the severest terms. 

The extraction of the cuspids is also to be condemned if performed for 
any other reason than a diseased condition involving contiguous parts. 
The loss of the superior cuspids is productive of a narrowing of the ante- 
rior portion of the arch, and depression at the corners of the mouth and 
alse of the nose. 

Delayed eruption of a permanent tooth, particularly the superior lateral 
incisors and the first or second bicuspids, are often productive of trouble- 
some irregularities. Delayed eruptions of the lateral incisor permits the 
cuspid to take an abnormal forward position, often approximating the 
distal surface of the central incisor, and making it impossible for the 
lateral to occupy a normal position ; while the non-eruption of a bicuspid 
permits the aj)proximati6li of the contiguous teeth, and often destroys the 
occlusion upon that side. 

Mouth-breathing, due to enlarged tonsils and adenoid growths in the naso- 



82 OPERATIVE DENTISTRY. 

pharynx, is also productive of a narrowing of the superior alveolar arch in 
the region of the bicuspids and protrusion of the anterior teeth. The writer 
is aware that in making this statement he places himself in opposition to 
some of the very best authorities upon the etiology of dental irregularities, 
but nevertheless he believes that the position of the upper lip and of the 
cheeks, when the mouth is open sufficiently to permit these subjects to 
breathe with comfort, is such that steady and continuous pressure is 
brought to bear upon the teeth and alveolar process in the bicuspid region. 
This force acting upon the crowns of the erupting permanent teeth, which 
as yet have their roots but partially formed, and have no bony support 
except the crypt in which they have been developed, and in this resorp- 
tion of the walls has been so considerable that the opening in it is much 
larger than the size of the crown, while, furthermore, the alveolar process 
is not formed around these teeth until after the crown is erupted, cannot 
but exert a moulding influence upon the j>osition of these teeth and their 
alveolar process, narrowing the arch at this portion and protruding the 
teeth in the incisive region. It seems to the writer that if these facts in 
relation to the evolution of the teeth and alveolar process are given their 
full weight in the argument, it must be acknowledged that mouth-breathing 
is as potent a factor in the production of this class of irregularities as that 
they are produced by an arrested or retarded development of the jaws, 
caused by the obstruction of nasal breathing. 

The habits of tongue- sucking and thumb- sucking may also be regarded as 
factors in the production of protrusion of the anterior teeth. Sucking of 
the tongue may, by the pressure upon the lingual surfaces of the superior 
and inferior incisors, cause a protrusion of the teeth of both jaws. While 
sucking of the thumb may cause a protrusion of the superior incisors by 
the pressure upon their lingual surfaces, and, when the thumb also presses 
upon the labial surfaces and morsal edges of the inferior incisors, it may 
cause an intrusion of these teeth. These habits do not, as a rule, cause 
irregularities of the deciduous teeth. This fact has been used as an argu- 
ment against the possibility of their causing a malposition of the perma- 
nent teeth. At first the argument seems good, but upon a careful study 
of the facts and conditions it will be discovered that these habits are rarely 
confirmed in the child until about the time that it is weaned from the 
breast or the bottle, which generally occurs when the child is from one 
and one-half to two years of age. 

The roots of the deciduous incisors are at this time nearly or fully 
formed, and the development of the alveolar processes is completed, thus 
rendering the teeth fairly stable and not easily moved from their posi- 
tion by such a form of intermittent pressure, while, upon the other hand, 
when the habits are continued to the period of the eruption of the per- 
manent incisors, it can be readily understood how, during the passage of 
the crowns of these teeth through the gums, and during the development 
of their roots and of the alveolar processes, a very slight amount of 
pressure, even though of an intermittent character, would be sufficient to 
divert them from their normal position to an abnormal protrusion of 
greater or less obliquity. 



CHAPTER Y. 

BACTERIOLOGY OF THE MOUTH. 

The discoveries which the science of bacteriology has made and is 
still making in reference to the causation of disease render it imperative 
that a knowledge of the bacteriology of the mouth should be possessed by 
the student and the practitioner who would approach a scientific study of 
dental and oral diseases, or who would be successful in their treatment. 

Bacteriology is one of the most exact of the medical sciences, and is 
governed by the most rigid laws, the slightest deviation from which often 
vitiating the results of long and laboriously conducted experiments. 

The student, therefore, who would hope to do original work in this 
line will need to cultivate exactness in methods and the most scrupulous 
obedience to those laws which have been found to govern the various 
phenomena of their natural and artificial growth, and the methods by 
which their various functions may be proved. 

~No treatise on operative dentistry written at the present day can be 
considered as at all complete which does not deal, to some extent at least, 
with the subject of oral bacteriology ; yet in a treatise of this size it will 
not be possible to give more than a simple outline of the subject in gen- 
eral, and this of necessity must be more or less elementary in character. 

Definition. — The term bacteriology is derived from the Greek /3aKr?/piov, 
a little stick, and ?.6yog, science. 

Bacteriology is that department of biology which deals with the origin, 
development, and functions of living micro-organisms. 

With the development of the science of bacteriology, or rather out of it, 
has grown the germ theory of disease. This theory, when first promulgated, 
had for its foundation the demonstrable facts that a certain few diseases were 
caused by specific germs, micro-organisms, or parasites. These statements 
of fact stimulated further research into the causation of other diseases, 
many of which, both medical and surgical, were found to be dependent 
upon specific micro-organisms which had gained access to the tissues of 
the body. 

These discoveries have revolutionized the practice of medicine and 
surgery in all their departments, but the greatest revolution has been in 
the practice of surgery. 

Without the discovery of the pyogenic bacteria and of the other path- 
ogenic forms now known to science, and without a knowledge of the prin- 
ciples of modern antisex>tics which grew out of these discoveries, much 
of the success which has been achieved in modern surgery during the last 
two decades would still be an impossibility. 

The achievements in modern dental surgery in the prevention and 
treatment of oral diseases have been due to the discoveries made in oral 

83 



84 OPERATIVE DENTISTRY. 

bacteriology and to the application of the same general principles of anti- 
septics. 

PARASITES. 

Definition. — Parasites are plants or animals which live upon other 
plants or animals. 

In the early history of bacteriology scientists found great difficulty in 
classifying some of the parasitic forms, from the fact that it was almost 
impossible to determine whether they belonged to the animal or vegetable 
kingdom. Nearly all of the parasites which enter the animal organism are 
microscopic in size, hence they have been designated as micro-organisms, 
microbes, or bacteria. Scientists are now generally agreed in classifying the 
bacterial forms as belonging to the vegetable kingdom. Bacteria belong 
to the fission plants, known as Schizophyta or Schizopliytes, a division of the 
ThallopJiyta, including those varieties which multiply by fission or division. 
These are divided into two sub-classes, those which possess chlorophyll — 
namely, the Oyanophycece (usually referred to as Algce) — and those having 
no chlorophyll, or the Schizomycetes (usually referred to as Fungi). 

1 ' Many of the bacterial forms are so small as to approach the limits of 
visibility, even when the highest powers of the microscope are employed." 
When located in the animal tissues, they are often demonstrated with the 
greatest difficulty, special staining reagents being necessary — sometimes 
double and triple staining being required — to differentiate them from the 
cellular elements of the tissues ; even then the demonstration may be 
unsatisfactory, and it becomes necessary to institute a series of experi- 
mental cultivations of the products of tissue disintegration in the case, 
and the inoculation of lower animals with the products of the artificial 
cultivations before a positive diagnosis can be reached. 

Miller, in his " Micro-organisms of the Human Mouth" (1882), ar- 
ranged those fungi which have a bearing upon the hygienic conditions of 
the body into four groups : 

1 . Fission fungi (bacteria) Schizomycetes. 

2. Mould or thread fungi Hyphomyceles. 

3. Bud fungi (yeast fungi ) Blaslomycetcs. 

4. Animal fungi (Pilzthiere) Mycetozoa. 

The first of the four groups, the Fission fungi, are the most important 
from the stand-point of health and disease, as they are the chief agents in 
the production of fermentations and putrefactions, and although through 
these processes they conserve the life and health of the vegetable and of 
the animal kingdom, by preventing the accumulation upon the earth's 
surface of dead vegetable and animal matter, reducing them to their origi- 
nal elements and returning them again to the air, the water, and the 
earth, they unfortunately have the power of attacking living organisms 
and exerting most baneful influences upon health and life, and are now 
recognized as being the active or exciting cause of a very large number of 
the diseases which attack the human body. 

The mould fungi (Fig. 226), although widely distributed in nature, have 
much less importance from the hygienic stand-point. They produce de- 



<f 



^* 



I * 






* r* ~ 



\ m 



%■ & * 



,i 






«f"*tf 



V 



Fig. 226.— Fruit mtm Id. (Shearer.) x 





H 



."*' «R& ** -•'•? 







is ■ . ir *'" 




Fie. 22'.). — Torula, or yeast funtri 



BACTERIOLOGY OF THE MOUTH. 



85 



compositions of organic substances, but with, less intensity, and with the 
exception of certain cutaneous diseases, thrush and ringworm, do not 
cause such profound disturbances in the human body as do the fission 
fungi, although abscesses and seropurulent peritonitis have been known 
to occur from inoculation. 

The bud fungi are even less important as disease-producers than the 
mould fungi. About the only diseases known to be produced by them are 
blastomycetic dermatitis and certain catarrhal changes. 

Fig. 227. 



«v#: 




Forms of bacteria. (In part after Fltigge and Zopf.) a, cocci ; 6, diplococci ; c, cluster-cocci (staphy- 
lococci) ; d, coccus chains (streptococci, torula) ; e, surface-shaped colonies (merismopedia) ; /, packet- 
shaped colonies (sarcina) ; g, a double coccus chain produced by a single fissation of each member in 
a direction at right angles to the long axis of the chain ; h, vibrioncs ; i, k, spirilla ; I, spirochetes ; 
m, spiromonades ; n, spirulina; o, cladothrix ; p, rods (bacilli) ; q, Clostridium ; r, leptothrix (threads) ; 
r', articulated threads ; s, rhabdomonas ; t, u, v, zoogloea. 



The animal fungi, or mycetozoa, are a group of fungus-like saprophytic 
organisms, the slime fungi or slime moulds. Most naturalists and bacteriol- 
ogists class them as fungi or as plant-growths of low type. E. E. Lankes- 
ter and his followers, however, group them with the protozoa, or lowest 
animal forms, while others have classed them as protists, or living organ- 
isms not decisively classifiable as either plants or animals. 

Of the animal fungi, mycetozoa, or slime moulds, very little is known. 
These organisms resemble huge masses of protoplasm, which are found 



86 OPERATIVE DENTISTRY. 

upon decaying vegetable matter. They are the supposed origin of certain 
plant diseases, such as the " finger and toe" of cabbage roots. 

Bacteria are divided into three general classes according to their form, 
— viz. , spherical cells, rod forms, and screw forms. Those which are rod- 
shaped are termed bacilli; those which are spherical are designated as 
cocci or sphero-bacteria ; while those with screw forms are called spirilla. 

Fig. 227 represents some of the common forms of bacteria. 



zopf's classification (modified). 

Group I. Coccacese. Spherical forms only. 

Genus I. Micrococcus (Staphylococcus) Division in one direction only, 
but irregular, so that the cocci after division form irregular clus- 
ters. 
Genus II. (Streptococcus) Division in one jdane, but regular, so that 

the cocci form chains. 
Germs III. Division in three directions at right angles to each other, 
and in two planes, so cubes are formed. 
Group II. Rods, straight or curved. At some period of life history, 
though cocci and other forms may occur. 
Genus I. Bacterium. Straight rods ; endospore formation does not 

occur. 
Genus II. Bacillus. Straight rods ; endospore formation occurs. 
Genus III Spirillum. Spiral rods ; spore formation does not occur. 
Genus IT. Vibrio. Spiral rods ; spore formation occurs. 
Group III. Leptotrichse. These are all thread forms. 
This is a practical and convenient classification. 

Pasteur classified all bacteria under two general divisions, from their 
relations to oxygen ; one division he termed Aerobes, the other Anaerobes. 

The aerobic bacteria require 
Fw. 228. the oxygen of the atmosphere 

in order to maintain existence, 
and therefore live upon the sur- 
faces of substances. 

The yeast fungi are examples 
of aerobic bacteria (Fig. 228). 

Fig. 229 shows one of the 

forms of yeast fungi— the torula. 

The anaerobic bacteria do 

not require oxygen to maintain 

existence, hence they live be- 

Various forms of yeast fungi, a, colonies of round „ „ 

cells (saccharomyces conglomerate?) ; 6, single Cells of neatll tne SUITaceS 01 liquids 

different forms partly forming daughter-cells ; c, cylin- an( I within the tissues of living 

drical cells of the pellicle fungus (saccharomyces myco- . , . „, -r. . . . , . . 

derma) bodies. The Bacterium teta.ni is 

an example of the anaerobic 

bacteria ; oxygen retards its growth or completely arrests its development. 

A very large proportion of all the bacteria are aerobic. Some of them 

are so dependent upon oxygen that even the slightest diminution in the 




BACTERIOLOGY OF THE MOUTH. 87 

amount is sufficient to retard or completely arrest their development. 
These are termed obligate aerobic bacteria. Others will develop equally 
well in a medium rich in oxygen, or where there is no oxygen, or rather, 
independent of the atmosphere. These are called facultative aerobic bac- 
teria. Nearly all the disease-producing forms of bacteria belong to the 
facultative variety. The fluids and tissues of the body contain a certain 
amount of oxygen, but this is soon consumed by the rapid growth and 
multiplication of the bacteria ; consequently their development would be 
arrested or their existence terminated did they not i^ossess the faculty of 
living under certain conditions without the presence of oxygen. 

" The capability of certain bacteria to proliferate and to manifest their 
specific action without access of air may explain the progress of tooth caries 
under air-tight fillings in cases where the softened dentin was not thoroughly 
removed before inserting the filling." (Miller.) 

Long exposure of certain forms of pathogenic bacteria to oxygen 
diminishes their virulence. Pasteur discovered that if artificial cultures 
were made of the bacterium of chicken-cholera and the cultures exposed 
to oxygen for a period ranging from three to eight months, the virus be- 
came very much attenuated. Cultures of the anthrax bacillus when 
treated in a like manner gave the same results. 

He found that if a chicken was inoculated with this weakened or atten- 
uated culture of the chicken-cholera bacillus, it was rendered immune to 
the action of the virulent virus, and that the attenuated culture of the 
anthrax bacillus prepared in the same manner rendered sheep immune to 
inoculations with anthrax, or if the disease was contracted after inocula- 
tion with the attenuated virus, it appeared in only a very mild form. 

Paul Bert has discovered that if the anthrax bacillus is exposed to 
oxygen under a laressure of twenty to forty centimetres, its vitality is com- 
pletely destroyed. 

Functions of Bacteria. — Bacteria are often classified according to 
their particular function ; for instance, certain species are disease-pro- 
ducing ; these are termed pathogenic. Other varieties produce color, — yel- 
low, white, green, etc. ; these are designated as chromogenic. Another 
species causes fermentation, and are called zymogenic. Another xDroduces 
gas ; these are termed aerogenic. Others are endowed with intense putre- 
factive properties and are known as saprogenic, while many others have 
not yet had their special functions discovered. 

A very large proportion of the bacterial forms are saprogenic. 

When classifying bacteria according to their relations to disease, it is 
customary to arrange them under two general divisions : 

1. Non-pathogenic, or those which do not as a direct cause produce 
disease. 

2. Pathogenic, or those which are the direct cause of disease. 

Fermentation and putrefaction are the results of the growth and multi- 
plication of certain forms of bacteria within the substances which ferment 
or putrefy. 

Among the non-pathogenic micro-organisms are included the sapro- 
phytic germs. These are sometimes spoken of as "nature's scavengers," 



88 OPERATIVE DENTISTRY. 

from the fact that they prey upon dead and decomposing vegetable and 
animal matter. These organisms may become indirect causes of disease 
when they gain access to wounds in which there are pent-up discharges and 
dying tissues. Under such circumstances they propagate with great 
rapidity, and produce certain poisonous and irritating substances called 
ptomaines, which when absorbed by the system give rise to symptoms which 
are denominated as septic intoxication, ptomaine fever, or septicemia. 

Such conditions may follow the death of a tooth-pulp, the extraction of 
a tooth, the wounding of the tissues of the mouth, or a compound frac- 
ture of the jaw. 

Pathogenic micro-organisms grow and flourish in the dead and dying 
matter, and invade the living tissues and destroy them. They also enter 
the circulation by direct inoculation through wounds and abrasions, and 
are carried to all parts of the body, and wherever deposited increase in 
numbers with amazing rapidity, forming fresh foci for the production of 
poisonous and irritating substances. The chief difference, therefore, be- 
tween the saprophytes and the pathogenic germs is, that the former act as 
indirect causes of disease by the production of poisonous substances, which 
are absorbed by the system ; but they have no power to penetrate the tis- 
sues or to enter the circulation, while the latter possess this power and act 
as direct disease-producing agents. 

The pathogenic bacteria may be divided again into two general classes : 

First. Micrococci. 

Second. Bacilli. 

Each of these classes has been divided and subdivided by the bacteri- 
ologist into an almost endless variety. This division and subdivision has 
been made necessary by the discoveries which have grown out of the more 
thorough and careful study instituted as to their size, form, and length ; 
their growth, grouping, and manner of propagation ; their action upon 
the various culture-media ; their chemical reaction ; the color imparted to 
the culture-media ; their susceptibility to the various staining reagents, and 
their action upon fermentable substances and living organisms. 

Investigation is constantly going on, and almost daily discoveries are 
being made of new forms of bacteria, or "further research into the life 
and habits of old forms develops new features and modes of action, which 
a little while before had not been dreamed of, while the etiology of cer- 
tain diseases which were before considered as obscure are one by one 
being cleared up by the discovery of a specific micro-organism, which, 
when introduced into the system in sufficient quantities, will produce the 
disease." 

The evidence which has been deduced in regard to the specific nature 
of the micro-organisms found in anthrax, typhoid (Fig. 230), tuberculosis, 
tetanus, diphtheria, glanders, leprosy, cholera, bubonic plague (Fig. 231), 
pneumonia (Fig. 232), erysipelas, actinomycosis, gonorrhoea, and suppu- 
rative inflammation is beyond dispute, while in many other diseases the 
evidence strongly points to the presence of a specific germ as the active 
cause of their development. 

The Micrococcus is an individual bacterium, the smallest of all the bac- 







*ft 



, X. 



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Fig. 230.— Bacterium typhosus. X 1000. 




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Fig. 281.— Bacillus pestis, and blood-cells of rat. ■; 1000. 




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Fig. 232.— Pneumococciis, showing capsule form. (V. A. Latham.) X 1200. 



«^?3K 



Fig. 233.— Diplococcus pneumoniae. (Frankel.) X'1000. 






Fig. 234.— Streptococcus pyogenes. (V. A. Latham.) X 1000. 



*ij*-**>* 



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£ 









Fig. 235.— Streptococcus in pysemia after erysipelas. (V. A. Latham.) X 660. 



. # m .< a — : — — ■ : — " 

Fig. 236.— Forms of bacteria in pus from an abscess. X 700. A, pus-cells ; B, micrococci and diplococci ; 
C, streptococci ; D, tetracocci. 



£ 



^ ' , / * 



Fl<;. 'i',7.— Bacillus tuberculosi 



BACTERIOLOGY OF THE MOUTH. 89 

terial forms, spherical, or nearly so, tiny, globe-like masses of matter, in 
some instances isolated, in others united in pairs, in fours, or in larger 
numbers, or arranged in chains or chaplets, or deposited in masses of 
zooglea or gelatinous matrix secreted by the bacteria themselves. 

When the micrococci are united in pairs they are termed Diplococci 
(Fig. 227, B), when in fours, Tetracocci (Fig. 227, D). When grouped in 
clusters they are called Staphylococci. When arranged in chains or chaplets 
they are known as Streptococci (Fig. 227, C). 

The pneumococcus or diplococcus of pneumonia (Fig. 233) is a good rep- 
resentation of the diplococci. 

Among the numerous difficulties which have to be met by the bacteri- 
ologist and the pathologist is the seeming identity of certain forms of bac- 
teria found in diseases presenting dissimilar characteristics ; for instance, 
the Streptococcus pyogenes (Fig. 234) seems to be identical with the Strepto- 
coccus erysipelatus (Fig. 235), the only discoverable difference being one 
of size, the coccus of erysipelas being the larger. 

The cocci multiply or propagate only by fission. The cell elongates 
prior to its segmentation, when a constriction appears in the centre, which 
becomes deeper and deeper until complete division of the cell into two 
equal parts takes place. These new cells soon attain the size of the parent 
cell, when they divide in the same manner, and so on ad infinitum. 

The diplococci, staphylococci, and streptococci are generally found 
associated with broken-down tissue and discharges which result from in- 
flammatory action, particularly in the pus-formations of acute abscesses 
and suppurating wounds (Fig. 236). These are termed the pyogenic cocci, 
or pus-microbes. 

The bacillus is an individual bacterium of rod like form. The bacilli 
include all of the elongated forms of bacteria, except the screw forms, and 
such as have a gyratory motion ; these are classed with the genus Spiril- 
lum. The bacillus tuberculosis (Fig. 237) is a good example of the short 
rod-like bacilli. 

A spirillum is an individual bacterium whose elements are curved, often 
forming a spiral of several turns. Koch's comma bacillus, which is found in 
the alvine discharges of patients suffering from Asiatic cholera, is a 
spirillum, and represents a simple curved variety, while Miller's spiril- 
lum, which is found in carious teeth, represents the screw or spiral form. 
Some of the spirilla have flagella attached to their extremities (Fig. 238.) 
The bacillus of hog cholera is an excellent illustration of a flagellated 
bacillus (Fig. 239). 

Some bacilli are rigid, others flexible ; some are motile, others non- 
motile, and they propagate either by direct fission or by endogenous 
spore-formation, — the formation of a cell within the body of the parent 
cell. 

Multiplication of Bacteria. — The process of reproduction in bacteria 
is a very rapid one. Fliigge observed the process of segmentation in a 
coccus to be completed in twenty minutes. Cohn has made the calcula- 
tion that if it should take one hour to complete the process of segmentation 
and for the new cell to attain the size of the parent-cell, one coccus, mul- 



90 OPERATIVE DENTISTRY. 

tiplying by this process, would in a single day produce 16,000,000 
progeny ; at the end of two days 281,000,000,000 ; while at the end of the 
third day it would have reached the enormous number of 46, 000, 000, 000, 000. 
Such figures are at first thought very startling, and if this multiplication 
could go on unhindered, the earth might soon be dominated by micro- 
organisms. There are, however, many circumstances which constantly 
oppose them ; one of the chief of these is their own delicate susceptibility 
to change of environment, the slightest difference in the soil, amount of 
oxygen, temperature, or moisture being sufficient in many instances to 
arrest their growth or completely destroy them. 

Various species are found growing together, but the struggle for ex- 
istence and of natural selection is as active here as elsewhere ; the stronger 
and more vigorous soon destroy the weaker. When they enter healthy 
living bodies they are attacked by the phagocytes and destroyed, or they 
do not find a congenial soil in which to grow, and either die or are swept 
out of the body by the excretory organs. 

The spore possesses an exceedingly dense enveloping membrane, which 
protects it from harmful external influences until such time as it finds a soil 
and environment suitable for its growth and propagation. 

The parent cell is usually enlarged at the middle or at one end by the 
growth of the spore, and when -it reaches its full development gelatinous 
softening of the cell-membrane takes place, the cell breaks up, and the 
spore is set free. The spore loses its tough enveloping membrane during 
its process of development, and is therefore more readily destroyed. 

The struggle for existence between certain species of bacteria found 
growing together suggested a therapeutic principle, the overcoming of one 
pathogenic species by the introduction of another, which many investi- 
gators have been trying to utilize for the benefit of mankind, though as 
yet with only partial success. Blood-serum therapy, however, is making 
rapid advances, and gives promise of being the most successful method of 
preventing or curing those diseases which are due to the introduction of 
micro-organisms into the system, or of their poisonous products. 

The growth of bacteria is also influenced by the presence of their own 
excretory or waste products ; for instance, the yeast plant ceases to grow 
after a certain amount of alcohol has been formed. 

The ammoniac fermentation of urine ceases when the ammonium car- 
bonate reaches thirteen per cent. (Fliigge.) 

In lactic acid fermentation the process ceases when the acidity has 
reached 0.75 to 0.80 per cent., and the micro-organism is often destroyed 
by the action of the acid which has been produced. 

Lactic acid fermentation of the carbohydrates takes place spontaneously 
in milk, in the juice of the sugar-beet, in the accumulations in the oral 
cavity, etc., and may be artificially induced by a large number of different 
bacteria in saccharine solutions. (Miller.) 

Acids and alkalies possess a certain amount of controlling influence in 
the growth of bacteria, especially the former. Acids in very dilute solu- 
tion retard the development of bacteria. There are, however, important 
exceptions to this rule, as, for instance, the Mycoderma aceti — acetic acid 




Fig. 238.— Flagellated spirilla and vibrio. X 2100. 



A*' 



Fig. 2:59.— Bacillus of hog cholera. (V. A. Latham.) X 1000, 



• \ 





\ 




* 


* #« * 




\ *' : • 'r. 




.» * * 








Fig. 240.— Staphylococcus pyogenes. (V A. 


Latham.) 


X 1000, 








Fig. 241. — Streptococcus pyogenes. X 3000. 




■'•'•"■■- 



■f • 



& 






V aft 




M^ 



Fig. 242.— Streptococcus hominis. (V. A. Latham.) v 218.75. 



BACTERIOLOGY OF THE MOUTH. 91 

bacterium — thrives best in a solution containing an excess of from one to 
two per cent, of acetic acid. Ten per cent, of acetic acid prevents the 
continuation of the acetic acid fermentation, while the Micrococcus urea 
thrives best in a high degree of alkalinity. With few exceptions, how- 
ever, a neutral medium is best adapted for the growth and propagation of 
micro- organisms. 

Heat and Moisture. — Two conditions are absolutely necessary for the 
germination and development of bacteria, — viz., a certain amount of heat 
and moisture. Both must be present, and in suitable amount ; the requi- 
site amount of heat minus the moisture, or the moisture minus the heat, 
is in neither case favorable to their development. 

This is eminently true in the treatment of dental caries and devitalized 
teeth ; with thorough desiccation of the properly prepared cavity of decay, 
or of the root-canal, and the prevention of the ingress of moisture by tight 
plugs, caries will be arrested in one case and suppuration prevented in the 
other. In no department of surgery is thorough antisepsis more inrportant 
than in operations upon the teeth. 

The temperature necessary for the growth of the majority of bacteria 
is 37° C. (98° F.). Mature bacteria cannot resist a temperature of 77° C. 
(170° F.). Most of them are destroyed when exposed to a temperature 
of 55° C. (131 F.), while spores have been known to resist 100° to 
120° C. (212° to 236° F.). A temperature of 100° C. (212° F.), if main- 
tained for ten to fifteen minutes, will effectually destroy the most per- 
sistent of spores. 

Spores resist the action of germicidal agents to a much greater degree 
than the bacilli which produced them, doubtless on account of the tough 
membrane which envelops them. 

Spores which have gained access to the tissues of the body may remain 
dormant for years, and give rise to no untoward symptoms until aroused 
to activity by the presence of conditions — environment — which favor 
their development and multiplication. 

Fiitterer reports having found the typhoid bacillus in the gall-bladder 
years after the initial attack of typhoid fever. 

Pyogenic or Pus Bacteria. — The pathogenic micro-organisms with 
with which the surgeon and the dentist has most frequently to contend are 
those which cause suppuration. 

The pyogenic bacteria by a specific action convert the inflammatory 
exudates, leucocytes, and the cellular elements of the tissues into pus. 
They are, therefore, termed pyogenic or pus bacteria. Of these there are 
several varieties, most of them of the globular or coccus form (Figs. 240, 
241, and 242). The number of bacterial forms which have been fully 
identified as the exciting cause of surgical diseases is not large, yet the 
statement may be safely made upon the basis of our present knowledge, 
that all traumatic infective diseases can be traced to the specific action 
of certain micro-organisms which have gained access to the tissues of the 
body. 

Koch laid down certain laws which he thinks should be used as the 
crucial test in establishing the specific disease-producing power of any 



92 OPERATIVE DENTISTRY. 

given organism : 1, it must be found in all cases of that disease ; 2, it 
must be found in no other disease ; 3, it must appear in such quantity 
and be so distributed that all symptoms may be accounted for by its 
presence ; 4, the organism must be capable of being isolated from the 
diseased tissues and be grown upon some artificial culture-media ; 5, when 
injected into an animal it must be capable of reproducing the disease. 
In many instances all of these conditions cannot be fulfilled, yet when a 
certain form or variety of micro-organism is constantly present in a par- 
ticular disease, it is fairly good evidence that it is the specific cause of 
that disease, although we may not be able to cultivate it artificially. 

Pathogenic Mouth Bacteria. — To Professor Miller of the Univer- 
sity of Berlin science is indebted more than to any other bacteriologist for 
our knowledge of the mouth bacteria. 

This author has shown in his most valuable work, the " Micro-organ- 
isms of the Human Mouth," that nearly all of the pathogenic and many 
of the non-pathogenic micro-organisms have been found in the human 
mouth. He has isolated and cultivated more than a hundred different 
species obtained from the human mouth, thus establishing the fact that 
this cavity is the receptacle and often the breeding-ground of a considera- 
ble number of specific micro-organisms, as well as the source through 
which infection of many serious and sometimes fatal diseases may take 
place. 

Among the more important forms of pathogenic micro-organisms which 
he found in the mouth may be mentioned the Micrococcus of sputum septi- 
cemia, Bacillus crassus sputigenus, Staphylococcus aureus and alhus, Strepto- 
coccus pyogenes, Micrococcus tetragenus, the Pneumococcus of pneumonia, and 
many others. 

MOUTH BACTERIA PROPER. 

Six forms of micro-organisms which are common to almost every 
mouth, and termed by Miller "Mouth Bacteria Proper," have the peculi- 
arity that no culture-medium has yet been found upon which they can be 
grown. Miller has experimented in hundreds of ways to cultivate them, 
but without success. 

These are the Leptothrix innominata, Bacillus buccalis maximus, Leptothrix 
buccalis maxima, Jodococcus vaginatus, Spirillum sputigenum, Spirochete den- 
tium (denticola). 

The term Leptothrix buccalis was first used by Eobin, and has been ap- 
plied to almost every living organism that has been found growing in the 
mouth. Miller thinks it should be banished from all bacteriologic 
writings on account of the confusion which it creates. He objects, also, 
to the term Bacterium termo, as it has so often been misapplied, some 
authors classing every organism showing a slight contraction in the mid- 
dle as Bacterium termo. 

Leptothrix Innominata. — This term has been proposed by Miller for 
those bacteria growing in threads, whose biology is too little known to 
define their relation to other mouth bacteria, or to form a separate group 
with distinct characteristics. 




Fig. 243. — Leptothrix bucealis. (V. A. Latham.) •; 193.75. 




«2»* *r "4 ' 



P5c>> *r<v|;- >---fV ^4.#, 



^- ■*^* — a i* - - — H* i 




Fig. 244.— Mouth bacteria. (R. R. Andre 



/.'. leptothrix Imecalis. 



BACTERIOLOGY OF THE MOUTH. 



93 



This organism is found in every mouth, but in varying quantities, 
depending largely upon the personal habits of the individual. It occurs 
in the soft white deposits which accumulate on the teeth ; sometimes it 
appears in masses, at other times it will be sparingly found (Fig. 243). 
These masses, according to Miller, vary in size, and consist apparently of 
small round granules, from whose margins thin, more or less zigzagged 
threads project. 

These granular masses form the so-called "matrix of Leptothrix buc- 
calis," and were formerly looked upon as its spores, but are in reality 
partly micrococci and partly only crossings of the threads themselves. 

The threads vary considerably in length, and are from 0.5/x to O.S/>. 
broad ; they are twisted, tortuous, immotile, and inarticulated, and take 
a faint yellow stain with iodine. They often appear degenerated or even 
lifeless. Shorter threads or rods are also found which may be either frag- 
ments of the threads or young cells (Fig. 244). 

Bacillus Buccalis Maximus. — This organism is the largest occurring 
in the mouth. The threads measure from 30 to 150/* long, the separate 
rods are from 2 to 10, a long and from 1 to 1.3/* broad. Miller found it in 
isolated threads, but most often 
in tufts, the threads having a 
parallel direction, separate bun- 
dles sometimes crossing each 
other. 

The rods have a very regu- 
lar contour, and are usually of 
the same thickness throughout 
(b, Fig. 245, is an exception). 
Iodine stains the majority of 
the threads brown-violet, either 
throughout or in isolated sec- 
tions. Miller has never found 
them in the dentinal tubuli ; their 
size would not permit their en- 
trance. Its size, the distinct and 
regular articulation of the rods, 

the absence of the zigzag windings, and its reaction to iodine, Miller thinks 
should preclude it from being classed with the Leptothrix innominata, 

Leptothrix Buccalis Maxima. — Miller has given this name to a form 
of Leptothrix threads which he found in the mucous deposits upon the 
teeth. He describes the organism as having long, thick, straight or curved 
filaments, which show a marked resemblance in form to the Bacillus buc- 
calis maximus just described, except that the joints are somewhat shorter 
in the latter. It does not give the iodine reaction. For these reasons he 
does not feel sure whether it is a different variety or the immature cells of 
the same variety in which the substance which takes the blue color is not 
yet formed. 

Jodococcus Vaginatus. — This organism is found almost universally 
in unclean mouths. Miller has never failed to find it except in two in- 




Bacillus buccalis maximus. 
solution. 



After treatment with iodine 
1S0O : 1. 



94 OPERATIVE DENTISTRY. 

stances of children, aged respectively five and six years. He describes it 
as appearing singly or in chains of from four to ten cells, longer chains 
rarely being seen. 

They are of coccus form ; the cells appear sometimes as flat disks, or 
rounded or even square-shaped bodies, being enclosed in a sheath. The 
chains have a diameter of 0.73 /-/.. He occasionally found chains from which 
one or more cells were missing, others whose sheaths had burst, but from 
which the cells had not as yet escaped. The sheaths do not show the 
iodine reaction, but remain colorless, or after continued action of the re- 
agent become yellow. The cell contents always take the stain, the shade 
varying from dark blue to violet. 

Spirillum Sputigenum. — This bacterium is present in all mouths, but 
in varying quantity. In cleanly mouths the numbers will be smafi, in 
those which are foul from neglect they often exist in prodigious numbers. 
They are found in the soft deposits at the margins of the gums. In neg- 
lected mouths with inflammation of the gums Miller sometimes found an 
almost pure culture of the organism. It is comma-shaped in form and has 
very active spiral movements, and when grouped together it forms short 
spirals or S-shapes. It is sometimes found in the dentinal tubules. It was 
for a time thought to be identical with the comma bacillus of Koch, — the 
cholera bacillus, — but Miller has proved it to be an entirely different 
species, from the fact that it cannot be artificially cultivated upon any 
known culture medium, while the Koch bacillus can be readily cultivated. 
Klein, however, has stated that the Spirillum sputigenum can be cultivated in 
acid gelatin. 

Miller discovered and describes two other forms of curved rods or 
comma bacilli which he found in the human mouth. The first is not 
difficult to cultivate, and occurs in short, plump, tapering rods, slightly 
curved and generally united in pairs. It is motile and multiplies by 
fission. 

The second occurs in the form of delicate rods of varying length, some- 
times straight, at others so curved as to form the arc of a circle, and when 
joined together at their ends forming a circle or letter O ; occasionally 
they are so joined as to form a letter S. They are non-motile, and multi- 
ply by fission, and during this process they form chains of cocci. This 
organism possesses many of the characteristics of the Finkler-Prior ba- 
cillus, but whether it is identical has never been determined. 

Spirochsete Dentium (denticola). — Miller found this organism (Fig. 
246) almost universally present, not, however, in decaying dentin, but in 
the same locations as the Spirillum sputigenum, — namely, at the margins 
of the gums, in the deposits found there, especially when the gingival bor- 
ders are in an inflamed condition. This organism is of spiral form, from 
8 to 25 ;jl long, of unequal thickness, very irregular windings, and with 
marked differences in their susceptibility to staining reagents. 

Miller is not sure whether they are two separate organisms, or only 
different stages in the development of the Spirillum sputigenum. 

In Fig. 247 it will be noticed that the same spiral or comma-shaped 
bacilli have flao-ellse. 



Jit 



$ ' 







Yi- 



Fig. 24t>. — Spirochseta dentium (denticola) and leptothrix threads. X 1000. 



'MP 



N 



/. vfA, 









V 






Fig. 247. — Spirochseta dentium (denticola), showing their fiagella. '■: 1000. 




Fig. IMS. — Leptothrix gigantea, from dog. > 750. 




r iG. 249.— Leptothrix giganten. (V. A. Latham.) 1000. 




Fig. 250.— Leptothrix gigantea. (Miller.) 1000. 



BACTERIOLOGY OF THE MOUTH. 95 

Leptothrix Gigantea. — This very remarkable organism (Fig. 248) was 
found by Miller in the mouth of a dog suffering from pyorrhoea alveolaris, 
and to which he has given the above name, suggested by its enormous 
dimensions. It grows in tufts or fascicles whose threads diverge from a 
common point of adhesion (Fig. 249). It forms cocci, rods, and threads, 
and therefore belongs to that group of bacteria known as pleomorphic, 
having more than one form. The threads of the individual tufts vary 
considerably as to their thickness ; some are very thin, others very thick. 
They sometimes appear straight (Fig. 250), at others irregularly curved 
or twisted into spirals. 

He did not determine its etiologic relations to the disease. In exam- 
ining the mouths of other animals — sheep, cattle, pigs, horses, dogs, cats, 
rabbits, etc. — he frequently found leptothrix-like fungi. 

Besides these micro-organisms, there are a very great number of others 
that are found at different times in the human mouth, many of which are 
pathogenic. Miller has made the estimate that in a certain very unclean 
mouth there were not less than 1,140,000,000 of micro-organisms. 

With such conditions as these it is not surprising that the human saliva 
is poisonous and sometimes possessing very virulent toxic properties, which 
may endanger the life of the operator who should be so unfortunate as to 
become inoculated with it through some wound or abrasion upon his 
hands. 

Biondi isolated from the human saliva five different forms of pathogenic 
micro-organisms, to which he gave the following names : Bacillus salivarius 
septicus, Coccus salivarius septicus, Micrococcus tetragenus, Streptococcus septo- 
pycemicus, and Staphylococcus salivarius pyogenes. Cultures of all of these 
organisms were found to be more or less virulent, causing death in mice 
and guinea-pigs in from twenty-four hours to fifteen days when injected 
subcutaneously. 

Miller has also found within the mouth a considerable number of other 
bacterial forms possessing pathogenic properties, four of which he exam- 
ined in detail and named as follows : Micrococcus gingivae pyogenes, Bacte- 
rium gingival pyogenes, Bacillus dentalis viridans, and Bacillus pulpce pyo- 



The first and second were found in the pus from pyorrhoea alveolaris ; 
the third was found in decaying dentin, and the last in gangrenous pulps. 

Cultures made from the first two and the last were found to be ex- 
tremely virulent, causing death, when injected into the abdominal cavity 
of white mice, in from ten to twenty-five hours. 

The Bacillus dentalis. viridans was not quite so virulent as cultures from 
this organism. When injected into the abdominal cavity of mice and 
guinea-pigs it produced death from peritonitis in from twenty-two hours 
to six days. 

Black, in his investigations of the mouth bacteria, found that the pyo- 
genic or pus-producing organisms were almost constant in this location, 
and says, " We must take into consideration the fact that the pyogenic bac- 
teria are generally present in the oral cavity, and endanger every wound 
we make in it." 



yb OPERATIVE DENTISTRY. 

Miller, in giving emphasis to the fact that the mouth, loaded as it is 
with so many forms of pathogenic micro-organisms, is a prolific source of 
infection, says, "The diseases caused by the pathogenic bacteria of the 
mouth may be considered under sis heads, according to the point of en- 
trance of the infection : 

"1. Infections caused by a breach in the continuity of the mucous 
membrane, brought about by mechanical injuries (wounds, extractions, 
etc.)- These lead either to local or general disturbances. 

"2. Infections through the medium of gangrenous tooth-pulps. These 
usually lead to the formation of abscesses at the point of infection (absces- 
sus apicalis), but also sometimes to secondary septicaemia and pyaemia, 
with fatal terminations. 

"3. Disturbances conditioned by the resorption of poisonous waste 
products formed by bacteria. 

"4. Pulmonary disease caused by the inspiration of particles of mucus, 
small pieces of salivary calculus, etc., containing bacteria. 

' ' 5. Excessive fermentative processes and other complaints of the di- 
gestive tract, caused by the continued swallowing of microbes and their 
poisonous products. 

"6. Infections of the intact soft tissues of the oral and pharyngeal 
cavities, whose power of resistance has been impaired by debilitating dis- 
eases, mechanical irritants, etc." 

Dr. Filandro Vicentini, in a series of articles published in the Inter- 
national Journal of Microscopy and Natural Science (1894-1895), upon the 
" Bacteria of the Sputa and the Cryptogamic Flora of the Mouth," an- 
nounces the discovery of a thread-like organism or Leptothrix, which he 
terms Leptothrix racemosa. This organism he first found in the sputa of 
pertussis, and afterwards traced to the mouth as its natural habitat, and 
which could always be found in the patina dentaria, — plaques of deposit, — 
located in the interdental spaces, if the material were gathered in the 
morning before the fast was broken, or some hours after a meal. This 
organism differed from the various forms of Leptothrix which had been 
recognized and described, in that the stems or filaments present a beaded 
appearance, and that these stems terminated in enlargements or heads 
which contained six or more rows of spores, as shown in Plate VI., 
Fig. 24. 

This micro-organism, he claims, passes through four xBases of develoj> 
ment and is therefore pleomorphic. The first phase being common to all the 
other species of bacteria, but which does not, however, represent its whole 
cycle of life, but only its primordial stage of immersed vegetation, or a vege- 
tation destined to propagate in a liquid or semi-solid media. 

In the second phase of the life history of the organism many degrees 
of transition may be observed. These are represented u by chains, bun- 
dles, and masses of intertwined filaments, isolated filaments, large dumb- 
bell bacteria of the type p, p, and_p', Plate V., and masses of diplococci ; 
the large dumb-bell bacteria being derived from the diplococci, the two 
original cocci linking together. The chains are often surrounded by 
masses of diplococci, while in the same chain small diplococci may alter- 



PLATE VI. 




W 

^ 



f rf 
* ^ 

l^# 



%24 

^ mm 

# Mi 
w ,<>i ' Ml 

;. ; /?* /<? ^ /Cr .# 




X/700 



Q[tpr[.Viareatin'i.deL 



BACTERIOLOGY OF THE MOUTH. 97 

nate with elliptical bacteria and rnecliura-sized dumb-bells, all perfectly 
equal, which form the largest number. ' ' 

The third phase is generally met with in the salivary calculus of the 
teeth. Its predominant elements are large filaments, often long, bent, 
and reunited in bundles, and stumps. Two notable features are observed 
in the large filaments, which have not been described by any previous 
author. The first of these is the division of the radial extremity of the 
filament into two or three branches (Plate VI., Fig. 9). "In a the filament 
is broken towards the top and exhibits two long roots ; in b there are three 
hood-shaped roots, both appearing to be swollen at their ends (c) like 
haustoria." The author raises the query of the use of these barbs or roots, 
if they are not to obtain a firm foundation in the soil. And to what 
purpose a firm foundation, if not to support higher forms of vegetation ? 

The second feature is that of the enlargement or "swelling of the ter- 
minal ends of the filaments, as shown in b and c, Fig. 9, and these are of 
varied form, at times containing a kind of nucleus. Plate VI., Fig. 26, a 
and &, show further development into heads or ears. There are other en- 
largements found along the filament, which might be styled knotty. 

"Intermixed with the other element — the stumps — are almost all the 
forms of bacteria, bacilli, spirilla, etc., besides a large number of very 
varied small chains, after the types shown in Plate V., c, d, k, i, x, 
and a/." 

The large size of the stumps he thinks may be accounted for by the 
fact that " the points of the filaments are removed by friction or other 
mechanical means, and this seems to impart a greater development to the 
remaining stems in the sense of greater thickness, as happens in the 
pruning of trees, through the retrocession of the ascending sap." This 
he thinks explains "the appearances of the stumps and their fragments, 
which are so various, and which led Miller to make of residual filaments 
two distinct species, — viz., Leptothrix buccalis maxima and Bacillus buccalis 
maximus, while the fertile filaments which he had discovered constitute 
Miller's third species, the Leptothrix irmominata." 

"From the tiny islands of the stumps in question spring at last the 
fructifications. The larger filaments gradually become thinner and pale, 
showing in their interior countless granules or parietal gemmules. These 
are the fertile filaments. They may spring either from the proper fila- 
ments with continuous contour or from the little chains, d, Plate VI., Fig. 
9, which are seen occasionally on the top of those filaments ; and in this 
last case, instead of a gradual thinning, may abruptly pass from the 
chain to the fertile filament," as shown in the figure. This phase the 
author terms incomplete aerial vegetation. 

The fourth phase he terms complete aerial vegetation or fructification. In 
this stage the fructification heads or ears have reached a developmental 
stage, which shows the formation of spores arranged in three rows (Plate 
VI., Figs. 10 and 13). 

' ' The fertile filaments are sometimes straight, at others bent or curved ; 
occasionally they are entirely wanting, because the fructifications have 
been carried away by mechanical force." 

7 ' 



98 OPERATIVE DENTISTRY. 

In Plate VI. , Fig. 10, at a, a, l k genimules of reserve' ' are seen adhering 
to the walls of the stem ; at b the little spores are j>roperly lodged ; at b' only- 
five are seen, the others having dropped ; at c the penultimate articula- 
tions of the stalk appear older and woody ; the last is granular, like the two 
articulations on the apex of the younger filament, d. 

The sporules, which are very small and round, are arranged in three 
vertical rows ; this is the appearance, almost without exception, in all the 
specimens observed, hence it is inferred by Vicentini that they are ar- 
ranged in six longitudinal lines. In several specimens stained with picric 
acid the prolongations of the stem into the interior of the fructification 
head could be distinctly traced. Staining with aniline colors rendered 
the viscid substance in which the sporules are suspended opaque ; but if 
glycerol was substituted for water in the preparation of the slide, the 
stalk after a long time reappears distinctly in all its length. The stalk 
and the ear form a continuous whole, and he likens a tuft of the organism 
with its vibrating ears to " a field of wheat. ' ' 

The length of the ears is frequently considerable, as shown in Plate VI., 
Fig. 16, the more conspicuous specimens being found in pulmonary sputum, 
" the largest being one-sixth of a millimetre." 

Bacteria in general are reproduced by two methods, — viz., by fission or 
cell divisions, and by the formation of spores within the parent cell, 
termed endogenous spore formation. Another method of reproduction is 
known as arthrosporous reproduction. By this process spores are formed 
out of portions of the cell-body, or some of the individual cells of the 
latter set free from the parent organism, the opposite of endogenous spore 
formation. Very little is known of this process at the present time. 

Still another method of reproduction may be mentioned : this is termed 
acrogenous abjunction, a process by which spores are formed at the apices 
of certain cryptograms. In this process the terminal cell becomes en- 
larged and transformed into what is known as a basidium, — a diminutive 
base, — from which external sprouts or sterigmata, bearing spores or sperma- 
tid upon their terminal ends, arise. 

Vicentini believes from his study of the Leptothrix raeemosa that it 
propagates by two distinct methods, the first by u internal gemmulation," — 
endogenous spore formation, — which he terms the u inferior or first cycle," 
and the other by " conjugated fructification^'' — acrogenous abjunction, — 
which he terms the u superior cycle." He claims that "the organism 
possesses real organs of reproduction by which it would resemble fungi and 
dioecious alga?, with distinct sexes upon different filaments or individuals. 

Its fertile filaments are at times engrafted, with two or three roots, upon 
clods or firm substrata, and end in fructification. The ears are linked 
together and fastened to a stalk, as shown in Plate VI., Fig. 16. Other fila- 
ments, however, less numerous than these, at times multiply, and lastly, 
branching off, bear certain productions by points, the male elements (Plate 
VI. , Fig. 14) or pseudo-inflorescences or blossoms formed of spindle-like 
(YZ, Fig. 14), snake-like, or comma bacilli {Spirillum sputigenuni), destined 
from all appearance, through their lively activity, to the function of con- 
jugation. 



BACTERIOLOGY OF THE MOUTH. 99 

This investigator was able to observe the complete process of fructifi- 
cation of the organism in sputa impregnated with its elements. The 
process is completed upon the fourth day by keeping it well sheltered in 
the dark. 

Vicentini makes the bold statement that he believes, from a study of the 
various phases through which the Leptothrix racemosa passes in its life his- 
tory, that it is with perhaps one exception the mother organism of all the 
bacteria and bacilli found in the sputum. He says, " Of the six primary 
species of fungi of the mouth, described by Miller, there would, in fact, 
exist only one, the Leptothrix buccalis of Eobin (Leptothrix innominata of 
Miller), or at most a second one, the Spirillum (Spirochete dentium of 
Miller). The other four types would represent, if we are not mistaken, 
only phases, or disintegrated particles of the microphyte, — viz., Bacillus 
buccalis maximus and Leptothrix buccalis maxima, fragments of the stumps 
that form the inferior layer of vegetation : the Jodococcus vaginatus series 
of special sheaths of bacteria proceeding from certain 'gemniules of re- 
serve,' enclosed in the filaments; the Spirillum sputigenum (comma bacilli) 
with our spindle-like and serpentine appendages detached from the pseudo- 
inflorescences (blossoms), and probably male organs. 

''All these particles or articulations cut from the mother plant (except 
the last, — viz., the copulative filaments) multiply by themselves, in va- 
rious ways, according to the condition of the nutrient substratum, in the 
liquid menstrua or on firm soil." 

He further suggests, as have some other investigators, that the patho- 
genic or virulent properties of bacteria are in all probability acquired as a 
result of their environment, and that it is not necessarily a permanent 
quality. 

This may explain the periods of activity and of immunity which are 
observed in relation to the progress of dental caries. 

Dr. J. Leon Williams, in an article in the Dental Cosmos (April, 1899) 
upon the ' ' Bacteriology of the Human Mouth, ' ' states that he, without 
knowing of the discovery of Vicentini, had some two or three years later 
made an identical discovery of the fructification of Leptothrix threads. He 
says, "While studying mouth bacteria I came across very regular arrange- 
ments of coccus forms about the ends of Leptothrix threads. At first I re- 
garded these as purely accidental. But the persistence and regularity 
of these forms in nearly every one of the preparations I was then making 
led me to examine them more closely, and I was astonished to find what 
appeared to be a thorn -like connection between the spore or coccus form 
and the leptothrix-like thread." 

After reading the work of Vicentini, which was brought to his atten- 
tion by a friend to whom he had mentioned his own discovery, Williams 
went forward with his work. His method of procedure is as follows : " A 
stream of sterilized water is thrown from a powerful syringe into the inter- 
dental space between the first and second upper molars. With a sharp, 
sickle-shaped instrument, previously sterilized, a gelatinous microbic 
plaque is removed, which appears upon the instrument as small, grayish- 
white material, which possesses considerable tenacity. This is placed 
L.ofC. 



100 OPERATIVE DENTISTRY. 

upon a clean watch-glass and covered with twenty or thirty drops of a 
thin, watery solution of methyl violet aniline, the mass being allowed to 
remain in the solution for twelve hours, but in the mean time occasionally 
teasing it apart to obtain a better penetration of the staining fluid. The 
fluid is then drained off and the mass washed first with sterilized water 
and then with a mixture of equal parts of glycerol, spirit, and water. A 
drop of the same mixture is then placed upon a cover -glass, the stained 
mass dropped into it, and teased apart as much as possible, and then care- 
fully inverted on a slide, care being taken to make as little pressure as 
possible upon the cover-glass. The preparation will now show fields sim- 
ilar to Figs. 251 and 252 if examined with a one-sixth-inch objective. 
Under a one-tenth- or one-twelfth-inch objective in fortunate specimens, 
fields like Fig. 253 will be observed. Such a view very clearly resembles 
a grass-plot, from which arise the blossom, fruit, or seed-heads of the plant. 
These are the fruit or spore-heads of a thread-like micro-organism, which 
I have found to be as constant as any form of bacteria in the human 
mouth." The Leptoihrix racemosa of Vicentini (Fig. 254) shows such a 
field under high magnification. 

This organism Yicentini describes as having ears or fruit-heads made 
up of six regularly arranged rows of spores or seeds. Williams has se- 
cured a few lucky views of the heads in cross-section, which show them to 
be composed of twelve rows or even more. 

The attachment of the spores to the central stalk by the thorn-like 
processes, sterigmata, or peduncles, and which constitutes the final and 
irrefutable proof of the correctness of Yicentini' s claim of the fructifica- 
tion of the Leptothrix racemosa, is most beautifully shown in Figs. 255 and 
256, while in Fig. 257 the spore attachment in both longitudinal and trans- 
verse section is likewise finely shown. Fig. 258 shows a transverse section 
under a magnification of about nine thousand diameters. 

Williams believes with Yicentini that the organism is one of very rapid 
growth and common to all mouths, and the forms which must result from 
the breaking up of the spore heads and stem of the organism are long and 
short rods, various sizes of micrococci, various sizes of diplococci, and various 
sizes of curved and club-shaped bacilli. He further says, "I have no dispo- 
sition to indulge in speculation over these discoveries, but here are the 
facts which must be reckoned with in all future considerations of the bac- 
teria of the human mouth and body. It would be folly to deny that these 
facts are big with possibilities. . . . However much we may be disposed 
to reticence, it is impossible to avoid asking what becomes of the enormous 
number of micro-organisms of different forms and sizes which are being 
constantly shed into the human mouth by this parent organism, and how 
many of them have been classified as permanent species. ' ' 

Upon this point Yicentini says, " According to my calculations not 
less than from two to three hundred trillions of germs or separated ele-. 
ments are generally present in the mouth and nose, liable to disseminate 
the species at every minute into other parts." 

There is a question, however, whether these organisms are not placed 
in the mouth by nature for a beneficent purpose. Fabulous numbers of 




Fig. 251. — The material from which this photograph was made, and all of those which follow, was 
obtained by scraping the approximal surfaces of teeth after thoroughly syringing with sterilized water, 
and, in some instances, also after rubbing the surface of the tooth with a wad of sterilized cotton-wool. 
The gelatinous mass of micro-organisms adheres to the surface of the enamel with considerable tenacity. 
The scrapings were stained with watery solution of gentian-violet-anilin water and mounted in diluted 
glycerol. Under a power of four or five hundred diameters places will be found presenting such 
appearances as are shown above. (.7. Leon Williams.) 




.•tifi cation heads of leptothrix racemosa. Zeiss objective 
(J. Leon Williams.) 




Fkj. 253.— Fructification heads of leplolhrlr racemom. (.1. Leon Williams.) 




•k growth of leplothrix raremosn fructification heads from appro 
high magnifying power. (J. Leon Williams.) 




r iG. 2.")5. — Fructification heads of Uplolli 




i'lG. 256.— Fructification heads of leptoth 




-Showing attachment of spores to central stem in both longitudinal and transverse section. 
(J. Leon Williams.) 




Fig. 258. — This photograph is from an enlarged negative made from an original photograph of trans- 
verse section of fructification head of leptothrix, racemosa. The original negative was magnified to 2000 
diameters. The enlarged negative and the above print represent an amplification of about 9000 
diameters. It shows the ceil wall and the shrinkage of the protoplasm caused by the action of the 
glycerol and spirit. The spore-stems, or sterigmata, are seen to arise from the central protoplasm and to 
pass through the cell wall. (J. Leon Williams.) 



BACTERIOLOGY OF THE MOUTH. 101 

them are constantly passing into the digestive tract, where they may, as 
suggested by Hallier, take an active part in the transformation of the in- 
gested food by the transmutation of the starchy elements into glucose, 
both in the mouth and the stomach. Miller and others have recognized in 
the buccal bacteria a peptonizing action equal to pepsin itself, even with- 
out the action of acids. 



BACTERIA WHICH AFFECT THE INTEGRITY OF THE DENTAL TISSUES. 

The zymogenic and the saprogenic micro-organisms have also a distinct 
interest for the dental surgeon from the fact that certain species of the zy- 
mogenic bacteria have for their special function the formation of acids 
within the mouth by the fermentation of the carbohydrates which are 
lodged there as alimentary debris, and also that certain other species of 
the saprogenic bacteria have the power of liquefying albuminoid sub- 
stances or digesting them by the production of a soluble ferment. 

According to the now generally accepted theory of dental caries, these 
micro-organisms are the j)rime factors in the production of this disease. 

The fermentation of the carbohydrates within the mouth is produced 
by certain species of bacteria, the results of which are the formation of 
various compounds, lactic acid, mannite, dextrin, etc. According to 
Miller, butyric acid is never found in the mouth except as a by-product in 
lactic acid fermentation. 

The fermentation of the carbohydrates is chiefly productive of the 
formation of lactic acid ; this is brought about by certain species of bac- 
teria acting upon these fermentable compounds and converting them into 
lactose and lactic acid, with or without the evolution of carbon dioxide. 
(Miller.) 

A considerable number of micro-organisms are capable of affecting 
this transformation. 

Miller, experimenting with twenty different species of mouth bacteria 
upon the carbohydrates, obtained in sixteen of them an acid resultant, 
while in one of the others, which was found in a putrid pulp, the evolu- 
tion of gas was so copious as to tear the gelatin into shreds. 

Vignal found, in his researches upon the mouth bacteria, that out of 
seventeen different varieties, seven of them liquefied coagulated albu- 
min, five others caused it to swell and become transparent, ten dissolved 
fibrin, nine dissolved gelatin, seven coagulated milk, six dissolved casein, 
three transformed starch, and nine converted lactose into lactic acid ; the 
majority, it will be seen, had a peptonizing effect, and some of them grew 
independent of free oxygen. 

The principal organism, however, in the production of lactic acid, and 
one which is constantly found in the human mouth, is the Bacterium acidi 
lactici of Hueppe. 

Among the carbohydrates which are most highly fermentable and 
readily acted upon by the lactic acid bacterium are the sugars, dextrin, 
starch, cellulose, etc., and these are always found in the mouth, in greater or 
less quantities, as alimentary debris, ready to be acted upon by zymogenic 



102 OPERATIVE DENTISTRY. 

bacteria. The mouth presents at all times the necessary degree of heat 
and of moisture for the rapid growth of these organisms. Lactic acid 
in very dilute solutions readily acts upon the inorganic substances of 
enamel structure and disintegrates it, and thus opens the way for caries 
to attack the dentin. The organisms which produce lactic acid enter the 
dentinal tubuli, where they continue to generate acid, which removes the 
calcium salts, while the liquefying or peptonizing action of other forms of 
bacteria dissolve the decalcified dentin matrix. 

Several other fermentations of carbohydrates take place within the 
mouth, by which mannite, dextrin, etc., are formed. 

Mannite is the product of a fermentation induced by an exceedingly 
small coccus — Micrococcus viscosus — which grows in chains in various sac- 
charine beverages, in wine, beer, etc., and in saccharine juices (Miller), 
and forms a gummy product known as mannite. Black believes that this 
substance is the cause of sordes which accumulate upon the teeth in the 
continued fevers, and that it may be the cause of thick, ropy saliva. 

Dextrin is formed as the result of fermentation caused by the action 
of a micrococcus — Leuconostoe mesenterioides — upon beet-juice and molasses, 
and can be induced artificially in saccharine solutions. (Miller.) 

Action of Pathogenic Bacteria. — The question of how the pathogenic 
bacteria produce their effects upon the living tissues of the body is one upon 
which there is still a wide difference of belief. Some observers are of the 
opinion that the symptoms of infectious diseases are the result of the for- 
mation by the micro-organisms of chemical substances of an irritating or 
poisonous nature, a sort of specific excretia. 

Others believe the phenomena, both local and constitutional, to be due 
to changes wrought within the tissues by the organisms themselves during 
their development, and that it is not necessary to assume the formation of 
a specific poison or virus to account for these phenomena. 

The action of the pyogenic or pus-producing bacteria is to produce 
local irritation or inflammation, while the chemical substances elaborated 
in the focus of infection are disseminated throughout the body, which, by 
virtue ol a jieculiar action, thought to be ferment-like, augments tissue 
metamorphosis, stimulates the u thermic centres" and thereby increases 
the body temperature, producing fever or systemic disturbance.. This 
condition is known as septic infection. 

The absorption of ptomaines without the presence of pathogenic bacte- 
ria will produce grave systemic disturbances. This condition is termed 
septic intoxication, or toxic infection. 

Ptomaines are powerful animal poisons developed by the process of de- 
composition of animal tissue in the presence of saprophytic bacteria. In 
their physiologic action they resemble the alkaloids, and when received 
into the circulation by the process of absorption they produce more or less 
severe constitutional symptoms. The "toxines" probably belong to this 
class of substances. 

The development of the ptomaines seems to exert a controlling or in- 
hibitory effect upon the growth of the micro-organisms. Many of the 
artificial cultures of bacteria, after a period of growth, cease to develop, 



BACTERIOLOGY OF THE MOUTH. 103 

. and it is partly by virtue of the formation of these substances that this 
controlling effect is brought about. 

Leucomaines are animal alkaloids which are produced within the living 
tissues by metabolism — tissue changes — independent of micro-organisms. 
The pathologic significance of these products is as yet not well defined. 

Immunity. — The effects of the virus of certain bacteria upon the vital 
fluids and the tissues of the body in certain diseases is to give protection 
against future attacks ; in other words, to render the organism immune. 

Pasteur believed this protection or immunity to be due to the ex- 
haustion of the chemical substances supposedly necessary to maintain the 
life and development of the specific bacteria. 

Fraenckel was of the opinion that the first invasion of the bacteria left 
behind certain substances which were inimical to the further development 
of the same species of micro-organisms, which might at some other time 
gain an entrance to the system. 

From the foregoing pages it will be readily appreciated that the diffi- 
culties to be surmounted in securing an aseptic condition of the mouth are 
so great as to make it an impossibility. 

Much can be attained, however, by a scrupulous attention to certain 
hygienic rules, — viz., brushing the teeth after each meal, followed by the 
use of floss-silk passed between the approximating surfaces, and the assid- 
uous use of antiseptic mouth- washes. 

Boric acid in fifty per cent, solution, cinnamon water, formal (one per 
cent.), listerine, pasteurine, and borolyptol are all valuable antiseptics for 
this purpose. 

Too much care cannot be exercised by the dentist and the surgeon in 
thoroughly cleansing the mouth and the teeth before commencing any 
operation which involves a breaking of the continuity of the soft tissues, 
and the thorough sterilization of all instruments and dressings used in the 
operation. A no less important precaution is that of thoroughly cleansing 
the hands and finger-nails of the operator, and washing them in antiseptic 
solutions. Failure to do this often results in the introduction of pyogenic 
bacteria and establishing suppurative processes, which with proper care 
might have been avoided. 

STERILIZATION OF HANDS AND INSTRUMENTS. 

Absolute cleanliness in all operations within the mouth is of such great 
importance from the surgical stand-point that too much stress cannot be 
laid upon its strict observance in every detail. This comprehends the steril- 
ization of the hands of the operator, of the mouth and teeth of the patient, 
of the instruments used in the operation, of the rubber dam, and of other 
materials employed for the exclusion of moisture. 

The student who would be successful in the treatment of the diseases 
and injuries to which the teeth and the mouth are subject must be taught 
to appreciate the value of antisej)sis and the technique of its employment. 

Carelessness upon the part of the operator in not observing the ordi- 
nary precautions of aseptic methods may not always result in spreading 
infection ; but this is due to the resistance of the tissues which have been 



104 OPERATIVE DENTISTRY. 

thus endangered, rather than to a lack of transmitting infectious material. 
Cases are on record in considerable numbers in which serious consequences 
have followed the employment of unclean or septic instruments in opera- 
tions like lancing an alveolar abscess, extracting a tooth, etc., some of 
which have resulted fatally. 

Among the most common infectious diseases which may be transmitted 
from one patient to another by the hands of the dentist and of his instru- 
ments are tonsillitis, diphtheria, suppurative inflammation, certain forms 
of stomatitis, malignant oedema, tuberculosis, and syphilis. In view of 
these facts, the operator should exercise the greatest circumspection in the 
cleansing and sterilizing of his hands and instruments when passing from 
one patient to another. The operator should never under any circum- 
stances permit himself to come in contact with his patient without first 
washing his hands, and this should be done in the presence of the patient, 
that there may be no lingering doubt about the question of cleanliness ; 
while the instruments which he is about to use should be taken fresh from 
the instrument-case, where they have been placed after being sterilized. 
Instruments should never be permitted to remain upon the operating-table 
after the patient has been dismissed, but should be immediately cleared 
away and placed in the sterilizing apparatus before the next patient takes 
the chair. Such attention to the appearances of cleanliness is very gratify- 
ing to the scruples of patients, and increases their confidence in their 
dental adviser that no effort will be lacking upon his part to insure them 
against the spread of disease by infection. 



TECHNIQUE OF STERILIZATION. 

Sterilization of the Hands of the Operator. — This may be accom- 
plished by thorough washing and scrubbing with hot water and antiseptic 
soap ; green soap containing two per cent, of carbolic acid is the best for 
this purpose. The finger-nails should then be carefully cleansed and the 
hands again washed in hot water. In cases of operation in which the soft 
tissues are to be involved the hands should receive a bath in a five per cent, 
solution of carbolic acid, or a 1 to 1000 solution of mercuric bichloride. 
The operator should also guard against his own infection by covering even 
the slightest abrasion of the cuticle of his hands with a film of flexible col- 
lodion. 

Sterilization of the Mouth and the Teeth of the Patient.— This 
comprehends the thorough removal of all calcareous and other deposits 
upon the teeth ; the filling of all carious cavities, either permanently or 
temporarily ; the treatment or removal of all suppurating teeth and roots, 
and a liberal use of antiseptic mouth-washes, like a saturated solution of 
boric acid ;■ two to three per cent, solutions of carbolic acid ; the Thiersch 
solution (salicylic acid 4 parts, boric acid 12 parts, water 1000), or solutions 
of listerine, borolyptol, pasteurine, or formol 1 to 100 of the forty per cent. 
solutions. 

Complete sterilization of the mouth and teeth, however, can never be 
attained by even the most rigid technique, but it may be so nearly approxi- 



BACTERIOLOGY OF THE MOUTH. 



105 






mated as to greatly reduce the dangers from infection in those cases where 
the continuity of the soft tissues of the patient has to be broken. 

Sterilization of Instruments. — Instruments of every kind should be 
thoroughly sterilized before being used upon a patient. This may be most 
efficiently done by boiling in water. All instruments which have been used 

Fig. 259. 





Instrument sterilizer. 



about the mouth of a patient should first be thoroughly scrubbed with 
warm water and soap, rinsed, and placed in a sterilizer and boiled for at 

Fig. 260. 







^ 



fr*-— 3 ^D 



Dental mirror. 



least five to ten minutes. Fig. 259 shows a very neat and efficient steril- 
izer, manufactured by the S. S. White Dental Manufacturing Company, 
which is sold at so moderate a price that every dentist can afford to possess 
one. 

When the instruments are removed from the sterilizer they should be 
w r iped dry with a clean, sterile towel while they are still hot. By this 
method the instruments will not rust or tarnish. Mouth-mirrors are some- 
times injured by the boiling process, but the best German makes stand 



106 OPERATIVE DENTISTRY. 

the ordeal very well, and will often last for months. Ash & Son and the 
S. S. White Dental Manufacturing Company supply a mirror (Fig. .260) 
which can be taken out of the frame, which makes it possible to sterilize 
this part of the instrument by placing it in strong solutions of carbolic 
acid, while the frame may be boiled. The safer method, however, is to 
boil these instruments like all others, and when the glass gives out replace 
it by a new one, which can now be done at trifling expense. 

Rubber dam may be kept in a sterilized condition ready for use by 
cutting it into squares of suitable size and placing it in a covered glass jar 
containing a 1 to 3000 solution of mercuric bichloride and washed in 
sterilized water before using. To guard against the possibility of carry- 
ing infection by the rubber dam from one patient to another it is best 
never to use the dam a second time, except upon the same patient. 

Gauze and cotton rolls are now prepared for the use of the dentist, which 
have been rendered sterile by prolonged heat. These should be kept in 
boxes with tight-fitting covers, and may be resterilized at any time by 
placing them in a sterilizing oven heated to 250° to 300° F. 



CHAPTEE VI. 

EXAMINATION OF THE TEETH AND MOUTH. 

The importance of frequent examinations of the teeth and oral cavity 
as a prophylactic measure against the development of disease and its early 
discovery cannot be too strongly urged upon the public or upon the practi- 
tioner. The old adage " that an ounce of prevention is worth a pound of 
cure" was never of more value than when applied to the prevention of dis- 
eases of the teeth and mouth. 

It has been said that "the highest aim of the healing art is not to cure dis- 
ease, hut to prevent it. 77 It should be, therefore, the highest duty of the 
dental surgeon to strive to prevent the development of disease within the 
oral cavity, and to check its ravages at the earliest possible moment, so 
that the attendant dangers may bs reduced to the minimum. In order to 
accomplish this much-to-be-desired result frequent examinations at stated 
periods, with instruction in the various means which may be adopted to 
keep the teeth and mouth in an hygienic condition, will be absolutely 
necessary. 

This system of frequent periodical examinations, to be most effective, 
should be instituted in early life, commencing with the little children as 
soon as the deciduous teeth are erupted. 

These examinations should be made as often as every three months in 
the case of little children. 

At these sittings the child should be taught by the dentist how to 
cleanse the teeth. This first instruction in the art may be rendered the 
more effective by the operator giving the child an object-lesson, by brush- 
ing his own teeth in its presence. The little patient should then be given 
a brush and induced to imitate the brushing process by watching the oper- 
ator as he apiDlies the brush to the teeth and makes the necessary move- 
ments in order to cleanse all the surfaces that can be reached by this 
method. The nurse or the mother of the child should be present, and in- 
structed to follow up the teaching each day, adopting the same methods 
of instruction. By the frequent examinations indicated the dentist has 
opportunity to learn whether or not his instructions are being followed 
and the child keeping its teeth and mouth clean, and if not, it gives re- 
peated opportunities to correct the habit of neglect and impress upon the 
child and those who are responsible for its care the importance of a hy- 
gienic condition of the mouth in preventing the development of disease. 

In the light of the prevailing theory of disease, and of the constant pres- 
ence within the mouth of so many forms of zymogenic and pathogenic 
micro-organisms, the practitioner would be remiss, indeed, who did not 
impress upon his clientele the great value of a hygienic condition of the 
oral cavity as a prophylactic measure. 

107 



108 OPERATIVE DENTISTRY. 

At each periodical visit tlie teeth should be thoroughly cleansed and 
polished, and a critical examination made in reference to the presence of 
caries, diseased conditions of the gums, or other abnormal manifestations, 
appropriate treatment being instituted for the relief of the individual ail- 
ment. 

This system can be followed with older children, young people, and 
adults, the intervals between the examinations being longer or shorter 
according to the exigencies of each individual. 

Children and youths during the period of rapid growth, chlorotic girls, 
and pregnant women have usually an increased predisposition to dental 
and oral diseases ; consequently it is the duty of the dentist to acquaint 
them with the fact that they should give increased attention to the care of 
their teeth and mouth if they would maintain these organs in a healthful 
condition. 

The writer has found in his own practice that his clients were very ap- 
preciative of this thoughtful attention to their physical welfare, and, as a 
rule, gladly co-operate with him in these endeavors. 

In order that no case requiring especial attention may be overlooked, it 
is his custom at the sitting given for the examination to record an engage- 
ment upon the appointment-book for the next examination, informing the 
patient that a notice of the engagement will be mailed a few days in ad- 
vance of the time when it becomes due. 

, These engagements, it is pleasant to say, are usually kept with great 
punctuality and evident appreciation. 

POSITION OF PATIENT AND OPERATOR. 

In examinations of the oral cavity good light is a sine qua non. An 
examination conducted with inadequate light is of little value, and a diag- 
nosis made under such conditions would be unreliable. 

The patient should therefore be seated in a suitable chair provided with 
a head-rest capable of being raised and lowered and moved backward and 
forward. The head of the patient should be so positioned that when the 
mouth is opened the light will fall directly within it. 

The operator should stand upon the right of the patient, with his feet 
firmly planted, the body erect, and the shoulders thrown back. The 
chair should be so elevated that the operator can maintain this position 
during examinations, and as far as possible in all operations. The stoop- 
ing position so often assumed by many operators is not conducive to full 
and regular breathing, and sooner or later will result in stooping shoulders, 
contracted chest, and pulmonary complaints. 

The operator should always be careful to breathe through the nose. 
Habits which produce a bad breath should never be indulged in. The 
contact of the operator with the patient should be at as few points as pos- 
sible. People of refinement and culture appreciate the efforts of the den- 
tist to guard them against any unnecessary contact of person. The dental 
chairs as made to-day are capable of such changes that the position of the 
patient can be suited to any requirement, so that the only contact that is 
necessary to support and guard the hands of the operator is that of resting 



EXAMINATION OF THE TEETH AND MOUTH. 



109 



the ends of the ring and fourth fingers upon some portion of the patient's 
face, while the fingers of the left hand control and guard the lips. 




Mouth-mirrors. 



INSTRUMENTS USED IN EXAMINATIONS. 

The instruments and appliances which are necessary to a thorough ex- 
amination of every portion of the crown of each individual tooth are of 
several kinds, — viz., mirrors, magnifying-glasses, explorers, electric mouth- 
lamp, floss-silk, separators, and wedges. 

Mirrors. — Plane and concave mirrors are both necessary in a critical 
examination of the tissues and organs of the oral cavity. The plane mir- 
ror gives the best and sharpest image, and is therefore the most important 

means of obtaining a view of the 
FlG - 261 - defects upon those surfaces of 

the teeth which are not in a di- 
rect line of vision. 

The concave mirror gives an 
enlarged but less distinct image ; 
its greatest value lies in its j)Ower 
of concentrating the rays of light 
and illuminating the obscure por- 
tions of the mouth. These in- 
struments should always be in the very best condition. A dull or 
scratched mirror cannot give a clear and distinct image ; such in- 
struments should therefore be discarded if the operator desires to 
perforin perfect operations. The most satisfactory mirrors are 
those backed by a deposit of pure silver ; they cost a little more 
than those "silvered" with tin and mercury, but the added cost 
is more than repaid by the brilliancy of the surface and their 
greater durability. 

Working by the Reflected Image. — Defects in the teeth so 
often occur in positions that are entirely out of the range of direct 
vision that it becomes necessary in order to bring such defects 
into view to employ the reflecting surface of the mirror. Many 
operations' have to be performed upon the teeth in which the only 
view of the field of operation is obtained from the reflected image in the 
mouth- mirror. 

The novice will at first find such operations exceedingly difficult from 
the fact that the image is reversed, and that each movement must be made 
in a direction opposite to that which appears to be correct. Continued 
practice, however, eventually overcomes these difficulties, and the operator 
is able to pass from a direct movement to a reverse one with apparently 
no effort of the will. It requires years of practice, however, and a high 
order of skill to make perfect operations under such circumstances. 

Magnifying Lenses. — These instruments are of very great value in 
detecting minute defects in the structure of the enamel, for observing the 
condition of fillings previously made, or the progress of an operation, and 
in the examination of the finished filling. 



110 



OPERATIVE DENTISTRY. 



The most useful lenses are those which, give a magnifying power of 
about four diameters. They may be either the watchmaker's glass (Figs. 
262 and 263), held in position before the eye by the muscles surrounding 
the orbit, or the lens mounted with a long handle, as shown in Fig. 264. 



Fig. 262. 



Fig. 263. 





Pointed eye-glass. 



Eye-glass. 



Such aids to the critical examination of the teeth are indispensable to 
the careful operator. 

The magnifying lens may be employed in two ways, either to directly 
magnify the parts which are in the direct line of vision, or by magnifying 
the image obtained of obscure parts by reflection upon the surface of the 
plane mirror. The enlarged image obtained in this manner is more sharply 
defined than that obtained by the concave mirror. The clouding of the 



Fig. 264. 





Magnifying lens. 

mirrors and lenses may be obviated by coating the surfaces with pure 
glycerol. 

Explorers. — These instruments are absolutely necessary for the detec- 
tion of surface defects in the enamel and at the margins of fillings. They 
are " essentially prolongations of the fingers, and convey impressions by 
their vibrations to the tactile nerves." (Jack.) They are principally used 
to search out defects in the sulci, fissures and grooves formed by the union 
of the developmental lobes of the enamel, and to explore those surfaces 
which cannot be brought into view either by direct or reflected light. 



EXAMINATION OF THE TEETH AND MOUTH. 



Ill 



Several different forms are necessary to reach all parts of the crown 
of the tooth, some straight, others of various curves or angles. Fig. 265 
represents some of the common forms. These may be made by the prac- 
titioner himself, or he can obtain them from the supply houses. 

No. 18 (American gauge) piano wire is the most suitable material from 
which to construct the points. The temper of this steel wire permits it to 

Fig. 265. 




Explorers. 



Fig. 260 



be bent into any desired shape necessary for this purpose, and is not so 
hard but that it can be filed to any degree of fineness compatible with the 
required strength and rigidity of such an instrument. These points may 
be mounted in wood or metal handles, to suit the taste and ideas of the 
operator. 

Electric Mouth-Lamp. — The electric mouth-lamp, or stomatoscope 
(Fig. 266), is a great aid in the detection of defects ivpon the proximal 

surfaces of the teeth. The lamp should 
be placed within the mouth, at the lin- 
gual surfaces of the teeth, and the cur- 
rent switched on. The light passing 
through the teeth renders them in a 
measure translucent, and defects upon 
their surfaces or fillings appear as dark 
shadows. Transillumination is also a valuable means of detecting the 
non-vitality of the pulp. Devitalized teeth do not transmit the light as 
readily as those having vital pulps. This is quite easily demonstrated 
with the electric stomatoscope, even in obscure cases. 
In detecting diseases of the antrum it is indispensable. 




Electric mouth-larnp (reduced). 



112 



OPERATIVE DENTISTRY. 



To obtain the best results by transillumination a dark room is necessary, 
especially for examinations of the antrum. Fluid or solid material (tumors 
of various structure) within the antrum obstruct the transmission of light 
and produce an opacity which can be detected by comparison with the 
normal opposite side and with the surrounding tissues. 

Floss-Silk. — Floss-silk which has been just sufficiently waxed to bind 
the fibres together is a very valuable adjunct to the explorer in the detec- 
tion of proximal surface defects of the enamel and in determining the 
condition of fillings. In a normally arranged denture, and in a crowded 
condition of the teeth, the finest explorers will not reach the approxi- 
mating surfaces ; the fioss-silk then becomes indispensable as an added 
means of detecting superficial lesions of the enamel, which is indicated by 
the character of the friction produced by moving it back and forth upon 
these surfaces, or by the fraying of its fibres. Very slight defects, how- 
ever, will sometimes remain undetected ; consequently implicit reliance 
must not be placed upon its negative evidence, and other means, when 
doubt exists, must be used to establish the conditions of these surfaces 
beyond peradventure. 

Fig. 267. 






Parr's universal separator. 

Separators and Wedges. — Separation of the teeth for the purposes 
of examination or in preparation for filling may be accomplished in several 
ways. Immediate separation may be obtained by the use of the Parr, 
Perry, or other screw or wedge separators (Figs. 267, 268), or by driving 
a wooden wedge between the teeth, or it may be accomplished more slowly 
by the use of waxed linen tape or india-rubber strips forced between them. 



THE EXAMINATION. 

A critical examination of the oral cavity should usually be preceded 
by a thorough cleansing and polishing of the teeth, as few mouths are so 
scrupulously clean that this procedure will not make the after-examination 
more sure and thorough. 

Certain parts of the teeth are more liable to be attacked by caries than 
others ; these are in locations which give ready lodgement and retention to 



EXAMINATION OF THE TEETH AND MOUTH. 



113 



food debris and sedimentary deposits, and in which fluids are retained or 
suspended by capillary attraction, — viz., the proximal surfaces, the sulci 
and fissures, and the labial and buccal surfaces; the relative liability to 
caries being in the order named. 

In conducting an examination of the mouth it is best to proceed in an 
orderly manner, that no part may be overlooked, and that every part 
should receive due attention. 

First. Notice the appearance of the patient as to the state of health. 

Secondly. A general view should be taken of the whole oral cavity, in- 
cluding the gums, the mucous membrane of the cheeks, lfps, palate, and 
fauces ; the tongue and the character of the oral secretions, and any devia- 
tion from the normal carefully noted, as these all have a more or less 
direct bearing upon the hygienic condition of the teeth. They are also 
indicative of various constitutional states and tendencies that influence the 
course and character of the dental diseases, the consideration of which 



Fig. 268. 






Perry's two-bar separators. 



should enter largely into the question which must always be decided, as to 
whether the best interests of the patient will be conserved by the intro- 
duction of temporary or permanent fillings. 

Thirdly. Beginning at the median line of each denture, a critical inspec- 
tion of every portion of each tooth should be instituted by the aid of the 
various appliances just described, and each defect carefully noted. Par- 
ticular attention should be given to those locations in which caries is most 
liable to be developed. The condition of all previous operations should 
be ascertained, and if imperfections exist they should be recorded, as 
should also the presence of salivary calculus, exposed pulps, devitalized 
teeth, pyorrhoea alveolaris, dento-alveolar abscess, the location of super- 
numerary teeth, irregularities, and teeth which have been lost. 

For the purpose of preserving the results of these examinations 
various forms of charts have been devised, with special signs adapted to 
simplify the work of making the record, any one of which will adequately 
serve the purpose. The operator can, however, use any of the diagrams 
which are found in the dental registers, inventing or adopting such signs 



114 OPERATIVE DENTISTRY. 

as seem best to him as a means of making a rapid, expressive, and reliable 
record. 

These temporary records should be preserved until the required opera- 
tions and treatment have been completed, and the record of each trans- 
ferred to the permanent register. 

The careful registration of all operations of whatever character cannot 
be too strongly urged upon the student and young practitioner, for as time 
goes on they become invaluable as a means of reference. 

No one can remember the exact condition of each and every denture 
upon which he has been called to operate in the past , nor the circumstances 
or difficulties which surrounded the performance of a certain operation, 
the condition of the pulp, or of the root-canals, etc., but many times such 
information would be of incalculable benefit to the patient and operator in 
the future treatment of the case. 



CHAPTER TIL 

DENTAL CARIES. 

Definition. — Caries (Latin, caries, rotten). 

Synonymes. — Caries dentes ; Caries dentium ; Dental decay ; Dental gangrene. 

Dental caries may be defined pathologically as a progressive molecu- 
lar disintegration of the structural elements of the tooth, beginning with 
the solution of the inorganic substances by the action of lactic acid formed 
within the mouth by fermentation, and terminating with the dissolution 
of the organic matrix through the solvent action of the saprophytic micro- 
organisms. 

Magitot defined dental caries from its clinical aspects as " a progressive 
softening and continuous destruction of the hard structures of the teeth, 
advancing constantly from the exterior to the interior, and causing a 
gradual disappearance of a more or less extensive portion, or even the 
whole of the organ." 

Introduction. — Dental caries is, without doubt, the most common of 
all the diseases to which the human body is heir, and from which very few 
persons among civilized nations entirely escape. It seems to be pre-emi- 
nently a disease of higher civilization, as it is most common among those 
nations which are recognized as having the highest civilization, and yet 
no race or tribe of men yet discovered, whether savage, barbarous, semi- 
civilized or civilized, ancient or modern, have ever wholly escaped it. 
Archaeology, history, and anthropology all prove the correctness of the 
statement. Evidences are not lacking that the prehistoric man suffered 
from dental caries, alveolar abscesses, and other dental diseases. Many 
of the Egyptian mummies found in our great museums show well-marked 
evidences of caries and other diseases of the teeth. 

Herodotus tells us that the Egyptians had doctors for the eyes, doctors 
for the ears, and doctors for the teeth, etc., showing that they had need 
of specialists in these directions. Lancets and forceps for the extraction 
of teeth are to be found in museum collections of Egyptian antiquities. 
Artificial teeth have been found in the mouths of mummies, and state- 
ments have been made, though not very well authenticated, that gold 
fillings had likewise been discovered in the teeth. They evidently pos- 
sessed some knowledge of dental therapeutics, for they applied the juice of 
the poppy, pepper, spices, etc., to relieve the pain of toothache, and in the 
later stages of this disease and in the early stage of alveolar abscess ap- 
plied the actual cautery and counter- irritation. One mummy in the 
British Museum, dating back to a period about 2800 B.C., or more than 

115 



116 OPERATIVE DENTISTRY. 

four thousand five hundred years, shows undisputed evidence of dental 
caries and other dental lesions. 

That dental caries and the lesions which result therefrom were com- 
mon among the Greeks in the earlier and later periods of their history- 
there is abundant proof. The early Greek physician gave considerable 
attention to the diseases of the teeth. During the latter part of the 
Greek epoch the fop or dude gave great attention to the care of his teeth, 
and was very proud of having them look fine and white. His more 
stalwart brethren ignored such attention to their personal appearance, con- 
sidering it effeminate and only suited to women and fools. Their physi- 
cians treated odontalgia after the manner of the Egyptians. Cicero 
credits the third iEsculapius with inventing an instrument for extracting 
the teeth. Diodes opposed extraction and treated toothache by medica- 
tion. Strabo mentions formulae for the relief of odontalgia and cosmetics 
for the care of the teeth. Dr. Schlieinann, the great Greek archaeologist, 
has reported that in his excavations at the site of ancient Troy several 
of the crania found there exhibited teeth with carious cavities, some of 
which had been filled with metals, lead particularly. 

Coming next to the old Eoman civilization, the historical proof is 
abundant that dental caries and other dental diseases must have been com- 
mon among them, and that they practised the art of filling carious teeth 
and of inserting artificial teeth carved from bone and ivory. 

Celsus gives formulae for the treatment of toothache resulting from 
caries. These were confounded from resinous and aromatic substances 
combined with the juice of the poppy, saffron, sulphur, etc., and were to 
be applied to the carious cavity in the painful tooth. He also advised 
the use of blisters and poultices for the cure of alveolar abscess, and in- 
sisted upon general medication in conjunction with the local treatment. 
Celsus has been given the credit of inventing the art of filling teeth with 
gold and other substances 150 to 180 a.d. Archseologic proof of the fact, 
however, that the art of filling teeth was practised by the ancient Romans 
is entirely lacking. Whether this is due to the quite general custom of 
burning the dead, and thus destroying the evidence, or that it had no 
real foundation in fact, is a question that may never be settled. 

RESULTS OF THE EXAMINATION OF ANCIENT CRANIA. 

Mummery has examined and tabulated a very large number of ancient 
crania in relation to the prevalence of dental caries with the following 
results : Ancient Britons of dolichocephalic type, 2. 94 per cent. ; of brachy- 
cephalic type, 21. S7 per cent. ; Eomano -Britons, 28.67 percent.; Anglo- 
Saxons, 15.78 per cent. ; ancient Egyptians, 41.66 per cent. It will thus 
be seen that the prevalence of caries bears a very close relationship to the 
degree of civilization and the luxurious habits indulged in by these ancient 
nations. 

Erofessor Broca examined a large number of crania of the ancient 
peoples of Europe, and discovered that caries of the teeth was much less 
frequent than at the present time, and that they were also very much worn 
down from attrition. 



DENTAL CARIES. 117 

Dr. Patrick instituted an examination of all the prehistoric crania to 
be found in the various important museums in America, composing Pea- 
body Museum of Harvard University, the Army Medical Museum, Wash- 
ington, D. C, the collection of Dr. Samuel G. Morton in the Academy of 
Natural Sciences, Philadelphia, the collection in the Davenport Academy 
of Science, Iowa, the collection in the Museum of the Chicago Medical 
College, Illinois, and a collection obtained from an. ancient burial mound 
near the great Cohokia Temple Mound in St. Clair County, Illinois, now 
in the Museum of the Missouri Historical Society at St. Louis. 

These examinations cover a wide range of subjects, including every 
evidence of the diseases and anomalies of the teeth and jaws, and form a 
wonderful mine of information, the importance of which can hardly be 
over-estimated, "for there is not a question that may arise in morphology, 
histology, or physiology on which the facts revealed in this investigation 
will not shed some light." (Patrick.) 

The crania examined included South Americans, Central Americans, 
North Americans, Europeans, Pacific and Sandwich Islanders, Egyptians, 
and Asiatics. Dental caries was found to be prevalent in all, but in a 
varying percentage, which seemingly is governed by the habits of life 
and the state of civilization. 

The South Americans included Peruvians, Chilians, Tierra del Fuegians, 
and Guanches. In this group 6719 teeth were examined ; 2462 were dis- 
eased, or 36.75 per cent. Number of carious teeth, 390, or 5.804 per cent. 

The Central Americans were composed of Mexicans, Guatemalans, and 
Nicaraguans. The teeth examined numbered 930, and of this number 
250 were diseased, or 26.8 per cent. Caries was present in 44, or 4.872 
per cent. 

The North Americans included Esquimaux, Alaskans, and various tribes 
from nearly every section of the United States. In this very large group 
27,362 teeth were examined : 3811 showed evidences of disease, or 21.4 per 
cent. Of this number, 1394 were carious, or 5.093 per cent. 

The Europeans included Germans, French, English, Swedes, Irish, 
Greeks, Italians, Anglo-Americans, and a few modern soldiers. The num- 
ber of teeth examined was 3422. Of this number, 1373 were found to be 
diseased, or 40.4 per cent. The number of carious teeth was 242, or 7.079 
per cent. 

The Pacific Islanders included Sandwich Islanders, Australians, New 
Zealanders, and Tchoolabees. In this group. 2738 teeth were examined, 
and 417 were found diseased, or 15.25 per cent. ; 118 showed caries, or 4.309 
per cent. 

The Egyptians included Africans. The number of teeth examined was 
3306 ; of these, 689 were found diseased, or 20.8 per cent. Of this number, 
113 were carious, or 3.418 per cent. 

The Asiatics included Malays, Chinese, Japanese, Armenians, Hindoos, 
and Burmese. In this group 2180 teeth were examined, and 336 showed 
evidences of disease, or 15.4 per cent. Number of carious teeth, 45, or 
2.064 per cent. 

Miller maintains that in the meat- eating races caries is far less preva- 



118 OPERATIVE DENTISTRY. 

lent than in those which subsist largely upon mixed foods, and presents as 
evidence the fact that the dolichocephalic ancient Britons, who subsisted 
in all probability almost exclusively upon a meat diet, presented in the 
crania examined only about three per cent, of dental caries, while in the 
brachy cephalic ancient Briton, Eomano-Briton, Anglo-Saxon, and Egyptian, 
all of whom subsisted upon a mixed diet, the percentage of caries ranged 
from fifteen to forty-one per cent. Among the modern aboriginal flesh-eat- 
ing races he cites the Esquimaux, Worth American (coast) Indians, North 
American (interior) Indians, South Americans, Feejee Islanders, New Zea- 
landers, and Lapps. These have all a low percentage of dental caries. 
The Esquimaux, who live almost exclusively upon meat and fish, have 
but 2.46 per cent, of caries, while the North American (interior) Indians, 
whose diet is mostly meat, but using some vegetables, have an average 
of 9.09 per cent, this being the highest percentage in this group of 
aboriginal meat-eating races. 

Magitot could find in the anthropologic series of the museums of 
Paris no examples of dental caries among the crania of the Mexicans, Pe- 
ruvians, or Patagonians, none among the aborigines of Australia, Mada- 
gascar, New Caledonia, etc., nor among the Malay and Javanese crania of 
Professor Wrolik. He also states that the African and Arab races are 
remarkable for the soundness of their teeth, the Caucasian race being the 
opposite of this, while the Mongolian race seems to hold a middle po- 
sition. The Icelanders, according to recent investigations, seem to be 
nearly exempt from the disease. 

The investigations of Barrett, conducted for the same purpose, also lead 
to the same conclusions. 

Prevalence. — Statistics upon the prevalence of dental caries among 
the nations of the present civilization are by no means numerous, and 
nearly all of those which have been taken deal more with the question of 
the frequency of caries in individual teeth and groups of teeth than with 
the subject of the percentage of people who are sufferers from the disease. 
That the percentage is very large and apparently upon the increase there 
is not the shadow of a doubt in the minds of those best qualified to judge, 
and yet without statistics carefully prepared from many sources, at stated 
periods and under varying conditions of life, any statement that might be 
made must be taken as one of personal opinion only. 

It is generally conceded, however, that females are distinctly more 
liable to dental caries than are males. 

Magitot expressed the relative frequency of caries in the female by the 
ratio of three to two as compared with the male. Harris places the ratio 
much higher, claiming that it occurs in the female three times as often as 
it does in the male. Married women are considerably more liable to the 
disease than the unmarried, as the period of pregnancy and lactation are 
especially favorable to the development and progress of the disease. 

In reference to the relative frequency of caries among the men of 
France who were subject to military duty, Magitot introduces the statistics 
of the war office. These statistics deal only with young men of twenty 
years of age, but they may be fairly considered as showing the regular 



DENTAL CARIES. 119 

percentage of badly defective dentures for the whole mass of the adult 
male population. 

The French law gave exemption from military service, first, when there 
was loss or caries of the incisors or canines of one of the jaws, and secondly, 
when there was loss or caries or a bad condition of the majority or of a 
large number of the other teeth. 

The exemptions from military service from 1837 to 1849, inclusive,— 
thirteen years, — by reason of imperfect dentures, was 25,918 out of 
3,295,202, which is equivalent to an annual average of 785 in every 
100,000 examined. The annual maximum was 895 in 1837 ; the minimum, 
643 in 1847, or an average percentage of 7.85. If there be added to this 
the increased percentage of caries in females, using Magitot's figures of a 
ratio of three to two, and taking an equal number of males and females, 
the percentage for the entire population would be 9.15. This, however, 
does not fairly represent the average percentage of persons afflicted with 
caries ; in fact, it falls far short of the actual condition, as all of those who 
were received were not free from dental defects, but simply were not suffi- 
ciently defective under the law to give exemption. 

Statistics which more clearly represent the true condition of the preva- 
lence of dental caries among civilized nations is to be found in the report 
of the School Committee of the British Dental Association (Tomes), fol- 
lowing the examination of the mouths of 3368 boys and girls at the Han- 
well and Sutton schools, and at the Exmouth training ship. Out of this 
number only twenty-three per cent, had sound dentures, or, in other words, 
seventy-seven per cent, were afflicted with caries. The number of perma- 
nent teeth found to be carious was 4543, while about an equal number 
of temporary teeth were found in the same condition. These boys and 
girls ranged from three and a half to seventeen years of age, but the 
majority were from five to fourteen. 

The number of boys upon the Exmouth training ship was 480, largely 
recruited from these schools, the average age being fourteen years ; twenty- 
four per cent, had perfect dentures, or, seventy-six per cent, had carious 
teeth ; 44.9 per cent, had from one to four carious permanent teeth, 22.9 
per cent, had from five to eight, and 5.25 per cent, had more than eight 
carious permanent teeth. At the Hanwell schools, out of 903 children 
examined at the age of eight years, 83 furnished 127 carious permanent 
teeth, all first molars ; at the age of twelve years 90 children had 244 
carious permanent teeth ; the percentage of unsound permanent teeth in 
this number of children at the age of six is 53 ; at the age of twelve, 271, 
and at the age of fourteen, 300. 

The Association Committee made an attempt to compare the condition 
of the teeth of the children in the poor and high-class schools, but the 
numbers in the latter were not sufficiently numerous to give conclusive 
results, as only 205 children of this class were examined, and these did not 
compare favorably with those less fortunately placed. 

Another interesting fact in reference to the prevalence of caries is the 
wide difference existing in the relative frequency of the disease in the upper 
and the lower jaw, and between individual classes and groups of teeth. 



120 OPERATIVE DENTISTRY. 

The differences between the right and left sides are so small as to be of 
no particular moment ; hence in the following tables this difference will 
only be noted in the footings. 

Ottofy computed from an examination of 14,644 teeth of American 
public-school children that caries was present in 27.33 per cent, in males 
and 32.67 per cent, in females. 

The teeth examined comprised 5100 deciduous and 9544 permanent 
teeth. 

Of the 5100 deciduous teeth examined the following percentage were 
found carious : 

Lower central incisors 0.03 

Lower lateral incisors 0.09 

Upper central incisors 1.32 

Upper lateral incisors 1.42 

Lower cuspids 1.99 

Upper cuspids 2. 78 

Lower first molars 6.52 

Upper first molars 6. 72 

Lower second molars. 7.80 

Upper second molars 9. 77 

Of the 9544 permanent teeth examined the following percentage were 
found carious : 

Lower cuspids 0.01 

Lower lateral incisors 0.04 

Lower central incisors - 0.05 

Upper cuspids 0.05 

Lower first bicuspids 0. 10 

Upper second bicuspids 0.28 

Lower second bicuspids 0.30 

Upper first bicuspids 0.38 

Upper lateral incisors 0.55 

Upper central incisors 0.85 

Upper second molars , 1.25 

Lower second molars 1.57 

Upper first molars 7. 20 

Lower first molars 7. 70 

This table gives a better showing for the American public-school 
children than that furnished by the committee of the British Dental Asso- 
ciation of the condition of the teeth of the children found in the Hanwell 
and Sutton schools. This difference is explained by the fact that the 
children in the Hanwell and Sutton schools were from the poorest class 
of English society, while the American public schools are patronized by 
all classes of society. 

The Schleswig-Holstein Dental Association, in a recent investigation * 
into the prevalence of dental caries among school- children in Northern 
Germany, conducted by Dr. Greve, of Lubeck, presents an extended 
report upon the subject, of which the following table is a summary : 

* Cor. Blatt. fur Zahn, July, 1899. 



DENTAL CARIES. 



121 



Six to eight years 

Nine to ten years 

Ten to twelve years. . . 
Twelve to fifteen years 



Number 
Examined. 


Perfect Teeth. 


Carious 




Number. 


Per cent. 


Number. 


6060 


407 


6.8 


5653 


4990 


268 


3.4 


4732 


3518 


149 


4.3 


3369 


5157 


172 


5.5 


4985 



Per cent. 

93.2 
96.5 
95.7 
94.5 



Of the 19,725 children examined, ninety-five per cent, showed dental 
caries. 

It was also noted that there were 372 anomalies of various characters, 
including harelip, cleft palate, irregularities, V-shaped jaws, and, singu- 
lar as it may seem, only one case of congenital syphilis was found. 

The investigation covered the children of nineteen towns. 

The boys were found to have somewhat better teeth than the girls, the 
difference being about three per cent, in favor of the boys. 

Magitot places the relative frequency of caries in the upper and lower 
jaw respectively in the proportion of three to two. 

This author presented the following analysis of ten thousand cases, from 
which the above conclusion is drawn : 



Central incisors 
Lateral incisors. 
Canines 



042 



First bicuspids 1,310 



Second bicuspids 1,310 



First molars 3,350 



612 upper. 

30 lower. 

747 upper. 

30 lower. 

445 upper. 

70 lower. 

940 upper. 

370 lower. 

810 upper. 

500 lower. 

1,540 upper. 

1,810 lower. 



Second molars. 



Third molars 



- 36 f 690 upper. 
I 1,046 lower. 



360 



220 upper. 
140 lower. 



Total 10,000 

Upper 6,004 -, in nnn Right side. 

Lower 



3 996 } 10 ' 000 Leftside 



10,000 
4,791] 
5,209 J 



10,000 



Hitchcock, in Wedl's " Pathology of the Teeth," presents the follow- 
ing table of twenty thousand cases prepared from records of fillings and 
extractions in which the ratio of frequency of caries in the upper teeth is 
placed at 1.9 to 1 in the lower, or nearly two to one : 



Central incisors 2,189 



Lateral incisors 1,954 -j 

Canines 1,261 j 



First bicuspids "..'.' 2,073 



2,101 upper. 

88 lower. 

1,827 upper. 

127 lower. 
1,058 upper. 

203 lower. 
1,588 upper. 

485 lower. 



122 OPERATIVE DENTISTRY. 

Second bicuspids 2,585 { !»£"> iiRPm 

870 lower. 
,273 upper 
1 2,126 lower. 



First molars 4,399/ 2,273 upper. 



Second molars 3,615 • 



1,675 upper. 
1,940 lower. 



Thirdmolars 1,924J , ^^ Pper - 

<- 1,025 lower 



Total 20,000 20,000 

Upper 13,136 \ 20 00Q Right side 10,151 \ 2Q 00Q 

Lower 6,864J~' Leftside 9,849 J ' 

Tomes presents a table of 2638 eases of extractions on account of caries 
or its consequences, as follows : 

Central incisors 25 

Lateral incisors 62 

Canines 36 

First bicuspids 227 

Second bicuspids 393 

First molars 1090 

Second molars 575 

Third molars 230 

Total 2638 

A table prepared by Pare and Wallis from the records of 30,012 cases 
of extractions at Guy's Hospital gives the following results in percentage : 

First molars 10,891, or 36.30 per cent. 

Second molars 5,904, or 19.68 per cent. 

Second bicuspids 4,179, or 13.93 per cent. 

First bicuspids 3,212, or 10.70 per cent. 

Third molars 2,639, or 8.76 per cent. 

Lateral incisors 1,202, or 4.00 per cent. 

Canines : 1,098, or 3.66 per cent. 

Central incisors 884, or 2.94 per cent. 

Separating the upper from the lower teeth in this table of cases, Pare 
and Wallis have given us the following percentage for the individual teeth : 

Lower first molars 5632, or 18.7 per cent. 

Upper first molars 5259, or 17.4 per cent. 

Lower second molars 3489, or 11.62 per cent. 

Upper second bicuspids 2503, or 8.33 per cent. 

Upper second molars 2415, or 8.04 per cent. 

Upper first bicuspids 2288, or 7.623 per cent. 

Lower second bicuspids 1676, or 5.58 per cent. 

Lower third molars 1322, or 4.4 per cent. 

Upper third molars 1317, or 4.38 per cent. 

Upper lateral incisors 1013, or 3.37 per cent. 

Lower first bicuspids 924, or 3.07 per cent. 

Upper canines 861, or 2.86 per cent. 

Upper central incisors 754, or 2.51 per cent. 

Lower canines 237, or 0.78 per cent. 

Lower lateral incisors 189, or 0.62 per cent. 

Lower central incisors 133, or 0.443 per cent. 



DENTAL CARIES. 123 

In these tables it will be noticed that the first permanent molars are 
most susceptible to those influences which produce decay, and that the 
lower molars are slightly more susceptible (18.7 per cent.) than the upper 
(17.4 per cent.), the difference being 1.3 per cent. The second lower mo- 
lars stand next in susceptibility ; these are followed by the upper second 
bicuspids and the upper second molars, and so on down the list until the 
lower canines, laterals, and centrals are reached, in which the percentage 
of decay is so small as to almost constitute immunity. 

The* agency which gives this protection or immunity is thought by 
some authorities to be the secretion of the submaxillary glands, by others 
the presence of fluid in the floor of the mouth, which is kept in constant 
motion by the movements of the tongue, and thus retarding the process of 
fermentation ; but whatever it is, the protective effect is not efficacious in 
the posterior part of the mouth, and it will be noticed that the agency 
grows less and less efficacious from the incisors backward. 

From the foregoing pages it will be readily seen that all of the inves- 
tigations in reference to the prevalence of dental caries among ancient 
and modern races conclusively proves that the disease has always been 
present, at least as far back as evidence can be obtained from written his- 
tory and archseologic research ; that it was comparatively rare among abo- 
riginal tribes and nations who per force lived a simple life ; while among 
those ancient and modern races and nations who had attained to a high 
state of civilization, with its attendant luxuries and enervating habits, it 
has been very common, while at the present time, as proved by the statis- 
tics recently gathered, it is increasing in a most alarming manner. 

etiolog-y. 

The causes which are responsible for the universal prevalence of this 
disease are many and varied. These are divided into two general groups, 
— viz. : 

Indirect or predisposing, and direct or exciting causes. The former deals 
with certain conditions which have been established beforehand, through 
inheritance of constitutional tendencies or special dyscrasia and local de- 
velopmental defects or anomalies ; while the latter treats of those phe- 
nomena which are the active agents in establishing and maintaining the 
progress of the disease. 

Predisposing Causes. — The conditions which are here enumerated as 
predisposing causes of dental caries may be divided into two groups, — 
viz., constitutional and local. 

The constitutional predisposing causes are : 

Environment. 

Climatic influences. 

Miscegenation. 

Excessive mental strain in growing children. 

Hereditary influence. 

Influence of inherited disease. 

Exanthematous disease. 

Continued fevers. 



124 OPERATIVE DENTISTRY. 

The local predisposing causes are : 

Structural defects of the teeth. 

Traumatic injuries. 

Irregularities in the arrangement of the teeth. 

Abnormal oral secretions. 

These causes are all more or less important factors in the predisposition 
and susceptibility of the teeth to caries, by reason of their influence upon 
nutrition and vital resistance, or of their local surroundings or environment. 

Upon a proper appreciation of the depressing influences of these con- 
stitutional conditions upon the function of nutrition and of vital resistance 
to disease, and the effort to correct or prevent these evil influences in 
the future, will depend in no small degree the perfection in structural 
development and the integrity of the teeth of the generations yet unborn. 

CONSTITUTIONAL PREDISPOSING CAUSES. 

Environment. — The term environment as here used is intended to 
include all those conditions of life which are the results of civilization, — 
viz., the physical, mental, and social conditions, and the food habit. 

It has already been stated that dental caries is most prevalent among 
those races and nations which have attained to the highest degree of civili- 
zation, and there can be no doubt that a deterioration of the teeth is a con- 
stant accompaniment of the progress of civilization. Why civilization 
should produce such effects is not a very difficult question to answer. The 
civilization of a race or a nation is a gradual process, and one which affects 
both the intellectual and physical development. The evolution of a savage 
or barbarous race to the plane of a civilized people is the work of centuries. 
The whole trend of thought and of moral obligation and responsibility to 
others has to undergo a radical change. With these changes come higher 
aspirations, an enlargement of intellectuality, and a desire for more 
knowledge. Knowledge is only attained by study and intellectual pur- 
suits, which of necessity greatly change the habits and mode of life. A 
savage, nomadic people, constantly warring with their neighbors, begin 
the process of evolution by forming confederations against a greater 
enemy ; they next intermarry, and later, because their common interests 
demand it, settle in communities and establish permanent homes. As 
their intellectuality increases, the older and wiser ones teach the younger 
the value of greater knowledge than they themselves have possessed, as 
this would give them an advantage over their enemies. Finally some one 
of their number arises whom they look upon as having more wisdom than 
the rest, and he becomes a leader, and perhaps a teacher of the tribe. 
Their language is developed, and characters are invented by which to 
express the language in writing. Later, schools are formed, in which the 
more ambitious are taught in the knowledge possessed by the wise men. As 
a result, larger communities are formed, industries spring up, cities are 
builded, the confederated tribes become a nation, and a ruler is chosen. 
Contact with other nations broadens the intellectual horizon and increases 
the ambition of the people to be equal to their neighbors. These ambi- 
tions stimulate a desire for wealth, and riches result in the introduction 



DENTAL CAEIES. 125 

of new and more luxurious habits of life and greater devotion to intellec- 
tual attainments and pursuits, as well as the capacity to enjoy them. 

The nation has now reached the plane of civilization. "With this evolu- 
tion has come higher mental and nervous endowments and greater capacity 
to enjoy and to suffer ; but this mental and nervous development has been 
very largely evolved at the expense of the physical system. The powers 
of physical endurance and of resistance to disease have been greatly 
lowered by the change in environment. War and the chase have given 
place to the counting-house and the shop ; the tent and the "dug-out" are 
now represented by the cottage and the mansion ; the simple diet of meat 
and a few vegetables, often uncooked, has been replaced by an endless 
variety of foods, containing large quantities of fermentable substances, and 
so prepared by the culinary art that the teeth and jaws get very little of 
the exercise which is so necessary to maintain them in a healthful con- 
dition ; while the use of food containing large quantities of such ferment- 
able substances as starch and sugar present the necessary elements from 
which the acids are formed which act upon the teeth, thus inducing dental 
caries and many other diseases as sequelae. 

Those nations of the present day which suffer most from dental caries 
are the Anglo-Saxons of America and Great Britain and the great 
European nations. The growth of modern dental science and the per- 
fection of the art among these peoples has been a work of necessity, and 
one which from its surgical aspects has kept pace in its development with 
the demands which have been laid upon it. 

But viewed from the more important aspect of prophylaxis, it has not 
yet attained nor kept pace with the ever-increasing needs in this direction. 
When one stops to consider how wide-spread and universal dental caries 
has become, and the increasing number of teeth that are destroyed by the 
disease every year, we are appalled by the problem, and wonder if the 
human race is not destined to become endentulous. 

The teeth of the present generation seem to be inferior to those of their 
immediate ancestors, while the children of to-day have, as a rule, a greater 
predisposition to dental caries than their parents. In other words, there 
seems to be a gradual deterioration in the structural development — per- 
fection of development — of the teeth, and a lowering of the resistive 
powers or the vital energy of the system against the encroachment of 
disease. 

Perfection in the structural development of the teeth of city-bred chil- 
dren of the middle and better classes of society is the exception, defective 
teeth the rule. Little children between the ago of three and six years are 
frequent sufferers from dental caries, odontalgia, and alveolar abscess, 
while very many have defective first molars which require attention as 
soon as they are erupted. 

This is the age of steam and electricity, of the lightning express train 
and the ocean greyhound, of the electric telegraph and the telephone. 

Men, and women too, have seemingly partaken of the energy and speed 
of these forces. It is an age of rush and of whirl. Men and women vie 
with each other and with their sex for place and power. In business and 



126 OPERATIVE DENTISTRY. 

social life, in educational matters, in their pleasures and vices, they go at 
high- pressure speed, and as a result often break down at a period of life 
when under more favorable circumstances they would still be in their 
prime. These conditions are manifest everywhere in the civilized world, 
but are most noticeable in the great cities, where the intensity of the 
struggle of the poor for existence and of the well-to-do and the rich for 
supremacy over their fellows in business, social pleasures, education, and 
display are the greatest. Children born under such circumstances have 
generally constitutions which are far from equal to those inherited by 
their parents, and as a consequence they are handicapped in their struggle 
for existence either by the direct inheritance of disease, or of tendencies 
and predispositions to disease which are the result many times of the 
terrible deprivations of poverty, or of overwork or over-indulgence in the 
luxuries and the pleasures of life, or of the indiscretions or the vices of 
their parents or earlier progenitors. 

Such an environment can only result in enervation, depression of 
vital forces, malnutrition, and defects in the mental, the nervous, and the 
physical development. 

Climatic Influences. — The influences of climate as a predisposing 
cause of caries in these days of immigration, colonization, and inter- 
national trade has come to be an important factor, and it should receive 
that recognition from the scientific men of the profession which its impor- 
tance deserves. 

It has often been remarked, especially in India and other tropical 
climates, that the white man was physically often very profoundly 
affected by the radical changes in the climate and environments. This is 
particularly noticed in the increased susceptibility to disease and in a 
lowered vitality or resistive power, so that it has become a recognized fact 
that these people must, as a rule, return to their own country every seven 
to ten years in order to recuperate their lowered vitality and physical 
stamina. The depressing effects of the climate are so severe to some indi- 
viduals that a residence of one or two years under its influences is sufficient 
to completely break their health. 

It can therefore be readily understood how such depressing and ener- 
vating influences acting upon the general system may lead to malnutrition, 
loss of nervous energy, vitiation of the secretions, particularly of the oral 
cavity and the alimentary tract, and thus act as predisposing causes of 
dental caries. That the teeth of the average Briton who takes up his 
residence in India for a period of years decay more rapidly than they did 
when at home seems to be the general opinion among them. The same 
opinion prevails among the American missionaries who have spent a 
number of years in India and other tropical climates. These opinions 
have been substantiated by the experiences of the British troops in South 
Africa and the United States troops in Cuba and the Philippines. 

It is a notable fact that in this country, which receives every year 
large additions to its population from foreign nations, principally from Eu- 
rope, these people, after a few years of residence, often suffer greatly from 
the ravages of dental caries. This the writer has observed to be the case 



DENTAL CARIES. 127 

more particularly among the Irish and Scandinavians. This tendency 
has been ascribed to various causes ; some authorities have maintained that 
it was due as much to a change in the food and social surroundings as to 
climatic influences. 

Wedl, in writing upon this point, says, "If it be true that geologic 
and climatic conditions, and the means of subsistence which are connected 
with the same, have such a preponderating influence in respect to the fre- 
quency of caries, then it is impossible to explain the fact that foreigners 
belonging to different races, who are exposed to the same conditions as 
the native inhabitants, still retain the typical structure of their teeth, as 
well as that of their bodies, and continue to furnish the proportion of 
dental caries peculiar to their race. This is found to be the case with the 
isolated Slavonic races of Austria and the descendants of the Celtic race in 
France." 

To this remark Hitchcock appends the following: "As geologic, cli- 
matic, and social conditions exercise a predominant influence upon the 
growth and development of the various races, mentally as well as physi- 
cally, it is evident that the development of the dental organs cannot fail 
to be controlled by the same causes. In this country, which is annually 
receiving large numbers of foreigners by immigration, the typical traces 
of race are usually effaced after the lapse of a generation or two, the de- 
scendants possessing all the peculiarities, and their teeth apparently being 
as liable to caries as the teeth of Americans generally." 

The personal observation of the writer leads him to the opinion that 
the children of immigrants born in this country are not, as a rule, as 
robust as their parents, and that they suffer more from dental diseases. 

Miscegenation. — The intermarriage of individuals representing dis- 
tinct nations and races has come to be a very common occurrence all over 
the civilized world. The railway trains, the steamships, the telegraph, and 
the submarine cable have broken down the barriers that once existed be- 
tween nations, and have stimulated the individual to seek knowledge, 
wealth, and home in other climates than his own, while the enlightenment 
which has followed in the path of these great inventions has swept away in 
large measure the religious and race prejudice which beforetime had pre- 
vented such alliances ; as a result, the human family is entering upon a 
course which is destined sooner or later to bring about an amalgamation 
of those contiguous nations and races which belong to the higher class of 
civilization. 

The crossing of distinct races, like the Anglo-Saxon and the negro, or 
the Mongolian and the Malay, produces a progeny which is in no way the 
equal, physically, of either of the races from which they sprang. The 
difference is principally noticed in a lowered state of vital resistance to 
disease and in the powers of endurance under physical strain. 

Miscegenation exercises a depressing influence upon the integrity of 
all of the structures of the body, tooth-structures included. The crossing 
of races and nations is not generally productive of benefit, especially when 
so widely separated as are those of the human species. " Human hybrids 
are notably deficient in physical completeness and vital power, nutrition 



128 OPERATIVE DENTISTRY. 

is more or less impaired, and the physiologic processes are weakened, so 
that the entire economy is depressed and abnormal." (Thompson.) 

These facts were so generally recognized in this country during the days 
of slavey, that the slave-dealer never made the mistake of buying mu- 
lattoes to fill an order for slaves to work in the rice-fields and sugar plan- 
tations of the far South, as these people did not possess the two great pre- 
requisites for this kind of labor, — viz., resistance to disease and superior 
powers of physical endurance. 

The mulattoes on this account were generally employed as house ser- 
vants, while the blacks were in demand as field-hands, because they pos- 
sessed in a much greater degree the necessary qualifications for hard labor 
and resistance to those diseases which are so common in the lowlands of 
the South. 

The half-breeds of the Malay Archipelago and the Eurasians of India 
are also examples of the degenerating physical effects of miscegenation. 

The effects of the amalgamation of nations is particularly seen in the 
American people, who are receiving a continuous stream of foreign and 
heterogeneous blood into their veins. "The depression that has ensued 
to the physique of the people of the United States as a natural result of 
these intermarriages may have contributed somewhat to the existing extra 
defectiveness of the teeth of Americans over those of nations who have 
been less subject to the effects of miscegenation." (Thompson.) 

Excessive Mental Strain in the Growing Child. — Excessive men- 
tal strain coming at that period in the history of the child when the de- 
velopmental changes are most active and when the nervous system is in a 
very exalted state and responds most acutely to all forms of stimulation 
and depression, is often productive of conditions which lower the general 
tone of the system and disturb the functions of digestion, assimilation, 
and nutrition, and thus lay the foundation for a train of physical ailments 
from which the child may never fully recover, while the nerve-centres 
may be so impressed as to produce nervous prostration, chorea, erjilepsy, 
paralysis, and kindred complaints. This lowering of the general tone of 
the system, the disturbance to the nutritive functions, and the nervous 
phenomena which may develop as a result of mental strain in growing 
children play an important part in the greater predisposition to dental 
caries so generally noticed at this period of life, by producing devel- 
opmental defects in the structures of the teeth, vitiated oral secretions, and 
rendering the child less able to successfully cope with disease-producing 
germs. 

The tendency of the age is to force children in their school work to the 
limit of what they are mentally and physically able to endure. This 
system applied to ambitious children often operates to their disadvantage, 
as they are inclined to go beyond their strength, and sooner or later the 
health is undermined, the teeth break down from caries, and, unless the 
strain is removed and the child given a complete rest, change of air, and 
surroundings, physical and nervous prostration are the result. 

The author has often found it necessary to advise parents and guar- 
dians to remove a child from school to save the health from being wrecked. 



DENTAL CARIES. 129 

In many of these cases the rapid decay of the teeth was the prominent 
symptom which attracted his attention and led to an investigation of the 
general health and surroundings of the child. 

Hereditary Influence. — Inherited tendencies or predisposition to 
caries of the teeth is often well marked in certain families. This predis- 
position is doubtless established by the transmission of some abnormality 
in the form of the teeth or by a direct structural malformation of the 
enamel or the dentin. The children of parents whose teeth have been lost 
early in life from dental caries are unquestionably very prone to be affected 
with like conditions. So well has this hereditary influence been estab- 
lished that it is not an infrequent experience to find special teeth in mem- 
bers of the same family attacked by the disease, and at relatively the 
same period of life. 

Influence of Inherited Disease. — Hereditary tendencies and predis- 
positions to certain diseases like tuberculosis, rheumatism, gout, various 
nervous affections, and insanity are often well marked ; but syphilis is the 
only disease that has been positively demonstrated to be directly trans- 
mitted from x>arent to child. 

The syphilitic virus predisposes to dental caries through its depressing 
influence upon nutrition and its tendency to attack epithelial structures, 
thus producing atrophy of the ameloblasts in those teeth in which the 
process of calcification is about to begin, and forming faults or imperfec- 
tions in the enamel which later become the starting-point of caries. 

If the student will refer to the chart showing the progress of calcifica- 
tion of the permanent teeth (Fig. 225, page 78), he will notice that the only 
teeth in which calcification is progressing up to the end of the second year 
of existence are the first molars and the central and lateral incisors, and 
these are the teeth which are always the most profoundly affected by the 
action of the virus in inherited syphilis. This will be readily understood 
when it is remembered that the most active stage of the disease in these 
unfortunate children is during the first 
and second years after birth. When this FlG - 269 - 

stage is prolonged to the third year the 
cuspids are also affected. 

Jonathan Hutchinson first called at- 
tention to the peculiar effects of inherited 
syphilis upon the permanent teeth, and 
offered the only adequate explanation of 
their malformation, — viz., interrupted nu- 
trition. These malformations consist of 
an atrophied condition or lack of develop- 
ment of the enamel upon the morsal surfaces of the first molars and the 
morsal edge of the incisors, with a notched condition of the morsal edge 
of the central incisors, semilunar in outline (Fig. 269). The incisors, both 
upper and lower, have often a stunted appearance, and are narrower at the 
morsal edge than at the cervix. The upper lateral incisors are sometimes 
'very much dwarfed, resembling pegs or inverted cones. Hutchinson re- 
garded the semilunar notch in the central incisor teeth as diagnostic of 




130 OPERATIVE DENTISTRY. 

inherited syphilis. This view has, however, been called in question, as 
the same condition has been noted in children to whom mercury had been 
administered in infancy until the system was profoundly impressed, but 
who had not inherited syphilis. And inasmuch as mercury is usually 
administered in inherited syphilis, the question has been raised as to 
whether the peculiar malformation is due to the effects of the virus or to 
the drug. On the other hand, the malformation is common in children 
with inherited syphilis who have received no treatment of any kind. It 
therefore seems probable that both the virus and the drug, by their de- 
pressing effects upon the functions of nutrition, are capable of producing 
these peculiar malformations. 

Teeth of this character are very prone to caries at those points where 
the enamel is defective or entirely lacking, and yet certain cases will resist 
the inroads of the disease for many years. 

Exanthematous Diseases and the Continued Fevers. — The exan- 
thems and the continued fevers occurring at the time of dental development 
retard or arrest this process for a shorter or longer period, according to 
the severity of the disease and the recuperative powers of the child. This 
interference with nutrition is indelibly impressed upon the developing 
teeth by pits and grooves which encircle the crowns of the teeth at that 
particular part of the enamel which was undergoing calcification at the 
time, or the enamel may be imperfectly developed at the morsal edge of 
the incisors and the cuspids, or at the cusps of the molars. Sometimes 
the enamel is entirely absent over a considerable portion of the crown. 

The teeth which are most liable to be affected in this manner are the 
first permanent molars, the incisors, and the cuspids. 

Various other diseases, like diphtheria, convulsions, and the gastric 
and intestinal affections, so common among children during the period of 
dental development, may produce like developmental defects. 

Cases of this character are of frequent occurrence. One of the most 
marked instances of this kind which ever came under the observation of 
the writer was a little boy ten years old, who was at this age in apparently 
good health, but rather small and slender for one of his years, and of 
strumous diathesis and nervous temperament. His tee,th up to this age 
had erupted at the normal period. The deciduous teeth had all been well 
formed, but very frail, and nearly all of them had been treated for caries. 
The permanent teeth which had so far erupted were the superior and in- 
ferior first molars, and the central and lateral incisors and first bicuspids. 
All of these teeth except the bicuspids were devoid of enamel over the 
whole extent of the crowns, except a narrow band at the cervical margin. 
The denuded surfaces were quite sensitive to the touch of instruments, or 
the action of acids, sweets, or thermal changes. The bicuspids were nor- 
mally developed. The child was born of a highly cultured but extremely 
nervous mother, with tubercular tendencies. For the first three years of 
his life the child was continually ill, suffering from gastric troubles and 
convulsions whenever there was any slight irritation to the nervous 
system. If his milk were ever so little changed by lactic acid fermentation, 
or he were ever so slightly overfed, convulsions usually followed, and it was 



DENTAL CARIES. 131 

only by the most careful nursing that he was carried through the critical 
period of first dentition. 

There is also a rapid increase in the progress of caries, as well as a 
greater predisposition or susceptibility to the disease in pregnancy, tuber- 
culosis, typhoid fever, diabetes, and other wasting diseases. Similar con- 
ditions prevail in ansernic and leukemic states. It is a noticeable fact 
that in young girls who are suffering from chlorosis the teeth often exhibit 
an increased tendency to caries and exceptionally rapid progress of the 
disease. 

Certain occupations have been thought by some authorities to predis- 
pose to caries ; for instance, millers, bakers, and candy-makers show an 
especial liability to caries, as do also workers in alkali, phosphorus, 
arsenic, chlorine, and sulphuric acid manufactories. 

LOCAL PREDISPOSING CAUSES. 

Structural Defects of the Teeth.— Structural defects in the enamel, 
the result of constitutional conditions which have impaired nutrition and 
thus prevented the proper development of this tissue, are a most impor- 
tant factor in predisposing the teeth to caries. The most observable of 
these defects have just been referred to,— viz., pits or honey-combed con- 
ditions, grooves, and the absence of enamel upon certain portions of the 
crowns. The less noticeable but more .important defects are those which 
may be found in almost all teeth, even of the most perfect development, — 
viz., the sulci, fissures, and pits formed by the union of the developmental 
lobes. Fig. 270 shows such a condition. At these points the enamel- rods 
many times seem to have been imperfectly cemented together, or the sulci 
and fissures are so deep as to give ready lodgement for food debris. These 
conditions invite the establishment of caries by making it possible for the 
micro-organisms of the disease to find a lodgement where, undisturbed, 
they may propagate and flourish. 

Many of the enamel defects are so infinitesimal in size as to require the 
aid of high-power objectives for their discovery, and yet they are suffi- 
ciently large to give lodgement to masses of micro-organisms. 

Structural defects of the enamel which leave the dentin exposed to the 
action of the micro-organisms favor rapid disintegration of this tissue ; 
but if the exposed surface of the dentin is of such shape or in such a loca- 
tion that the lodgement of bacteria can be prevented, caries will be no 
more likely to occur at these points than upon the enamel itself. 

The rapidity with which caries progresses in the dentin will depend 
in large measure upon the character of the structure of this tissue. Den- 
tin in which the interglobular spaces are numerous does not seem to possess 
the same degree of resistance to the invasion of the micro-organisms of 
decay as those teeth which are more perfectly organized. 

Black has shown very conclusively that the chemical constituents of 
the teeth do not exhibit a sufficient variation to account for the differences 
observed in the rapidity with which structural disintegration takes place 
in caries, and that the variations in the amount of lime-salts in the dentin 
are not enough to explain their variation in hardness. 



132 OPERATIVE DENTISTRY. 

It must be conceded, however, that alterations in the structural organi- 
zation and chemical constituents of the dentin modify to a greater or less 
extent the progress of the disease. "The forces of attack being equal, 
a poorly organized and badly formed tooth will succumb sooner than one 
perfectly formed and of completely organized tissues ; this law is constant 
in all biology." (Burchard.) 

Another structural defect which predisposes to caries is the deviations 
from the normal in the external forms of the teeth. Teeth of the most 
perfect form are broader at their morsal surfaces than at the cervix ; in 
other words, are bell-crowned. This form of tooth in a normal dental 
arch permits approximal contact with each of its neighbors at one point 
only, — viz., near the morsal margin of the approximal surface of the 
bicuspids and molars and the morsal edge of the incisors and cuspids, thus 
separating each tooth from its fellow by Y-shaped interspaces, which are 
generally kept clean by the passage through them of the fluids of the 
mouth. If, on the other hand, the labio-lingual diameter of the crowns 
is much greater than the mesio-distal, and the apj)roximal surfaces are 
flattened, these surfaces of the teeth lie closer together, nearly if not quite 
obliterating the proximate interspaces, thus making it difficult or impos- 
sible to keep them free from alimentary debris, and favoring the lodgement 
and growth of the bacteria of fermentation. 

Traumatic Injuries. — Defects in the enamel caused by traumatic in- 
juries are not nearly so common as the developmental defects, and are 
not, as a rule, so liable to become the starting-point of caries. Injuries 
which fracture the enamel, leaving the dentin exposed, if occurring at 
points which are subject to the friction of mastication, or of such shape 
as to be self- clean sing, rarely develop caries ; but when the reverse is the 
case, caries will often be established in a very short time. Injuries which 
cause crushing or splitting of the enamel without dislocation of the frag- 
ments are much more liable to become the starting-point of caries than 
those fractures which cause loss of tissue, from the fact that they offer 
much more favorable conditions for the entrance of bacteria and their 
undisturbed propagation. Fig. 271 shows caries following a crack in the 
enamel. 

Irregularities in the Arrangement of the Teeth. — Teeth which 
are irregular in their arrangement in the arch, no matter how perfect they 
may be in structure and form, have a much greater predisposition to 
caries than those which have a normal arrangement. 

Nature in constructing the typical dental organs of man and arranging 
them in the perfect arch, placed them in the best possible condition to 
withstand the action of those destructive agencies which continually sur- 
round them. Any deviation from this perfection of form and arrange- 
ment must, therefore, necessarily predispose the teeth to be acted upon 
by these agencies, while the degree of predisposition will be largely con- 
trolled by the character and degree of the irregularity in form and po- 
sition. 

By mal- arrangement of the teeth certain of their surfaces are rendered 
very difficult or well-nigh impossible to cleanse by natural or artificial 



Dental fibres, 
penetrating 
the enamel 




Fig. 270.— Section of human molar, showing caries of enamel following a fissure. X 95. 



Caries follow- 
ing crack in 
enamel 



Dentinal tuluili ■ * 1 .! || S 
entering the W I 

-nainel • ' M M'WI (I 




Fig. 271. — Caries following crack in enamel. X '.5. 



DENTAL CARIES. 133 

means, and thus the active agencies of caries are furnished with the best 
possible conditions for the establishment of their destructive work. 

Injuries, extractions, or the necessary loss of a tooth often cause mal- 
position of adjoining teeth, and render the approximal surfaces more diffi- 
cult to be cleansed by the natural agencies of the mouth, and by that much 
establish a greater predisposition to caries. The injudicious use of the 
file is also a predisposing cause of caries, and secondary caries is often 
invited by failure to restore the normal contour of the teeth when inserting 
approximal fillings. Broad contacts upon the approximating surfaces of 
the teeth are grave deviations from the normal condition of a perfect 
dental arch, and should never be allowed to obtain as the result of opera- 
tion, as all such conditions invite a recurrence of the disease. 

Abnormal Oral Secretions. — Normal mixed saliva is generally alka- 
line in its reaction. Parotid saliva is faintly alkaline, while the secretion 
from the submaxillary glands is more strongly alkaline, as is that from the 
sublingual glands. The secretion from the parotid is a clear, watery fluid, 
while that from the submaxillary glands, though a limpid liquid, is quite 
viscous, a quality which under the influences of cold gives it an almost 
gelatinous consistence. 

The secretion from the sublinguals is a limpid viscid fluid, but rich in 
ptyalin, which gives it a ropy consistency. The secretion from the buccal 
mucous glands is also a viscid fluid, rich in mucin, and has an acid 
reaction. 

Changes in the character of these secretions often take place as a result 
of certain morbid conditions of the mouth or of the general system. 

The morbid oral conditions which may induce alterations in the 
character of the saliva are stomatitis in its various forms, gingivitis, 
tonsillitis, pharyngitis, and diphtheria. These inflammatory conditions 
greatly augment the secretion of buccal mucus, and as a consequence 
there is a marked increase in the acidity of the oral fluids. This is made 
evident by the use of litmus paper, and "by the solution and consequent 
disappearance at such times of deposits of tartar." (Magitot.) 

The morbid conditions of the general system which may induce altera- 
tions in the character of the oral secretions are certain acute and chronic 
diseases. 

Among the general acute affections which may produce these effects are 
the eruptive fevers, typhoid and malarial fevers, pneumonia, bronchitis, 
pleurisy, gastritis, enteritis, and the constitutional effects of such drugs 
as mercury, potassium iodide, etc. 

In all of these conditions it has been observed by various writers, 
from Donne (who called attention to these facts in 1835) to the present 
time, that the oral secretions presented an acid reaction, and that accom- 
panying this condition there was hypersensitiveness of the teeth, with an 
increased predisposition to caries. 

The general chronic affections in which these changes are most often 
noticed in the oral secretions are rheumatism, gout, dyspepsia, chronic 
enteritis, dysentery, gastralgia, and pulmonary tuberculosis. "Their 
effect is to exaggerate the production of ptyalin, the agent of viscidity. 



134 OPERATIVE DENTISTRY. 

and to excite a hypersecretion of mucin, two phenomena caused either by 
the direct influence of intestinal alteration or by reflex action of the gen- 
eral condition upon the conditions of the mouth." (Magitot.) 

Like conditions are frequently observable in certain physiologic states, 
as in pregnancy and lactation. Acid reaction of the saliva and hyper- 
sensitiveness of the teeth, with an increased predisposition to caries, is so 
common among women during these states that the tendency among them 
at these times to lose their teeth has been crystallized into the terse adage, 
" for every child a tooth." 

In mouths which show an acid reaction of the saliva it is common to 
find an increased quantity of ptyalin and mucin, which give an albuminous, 
ropy appearance to the secretion. 

These substances, being capable of coagulation, give a tenacious char- 
acter to the saliva and cause it to cling to the surfaces of the teeth, thus 
forming a convenient medium for the growth and destructive action of the 
bacteria of decay and the retention and fermentation of food debris. 



CHAPTEE VIII. 

DENTAL CARIES (CONTINUED). 

The agents which are immediately responsible for the production and 
maintenance of a disease are termed its direct, exciting, or active causes. 
These causes are often obscure, and many times entirely hidden from 
observation. 

Dental caries was thought by many of the older writers to be analo- 
gous to caries of tone, but this cannot be the case, for the physical phe- 
nomena of disintegration of these tissues are so very different. Caries of 
the bone is an inflammatory molecular disintegration of tissue, a retrograde 
metamorphosis. The organic and inorganic substances or elements are 
dissolved or break down together, and are carried away in the sanies or 
pus which is formed as a result of the inflammation. 

In caries of dental tissue there are no inflammatory symptoms except 
that of increased sensibility. Modern research has demonstrated that 
caries is caused by zymogenic organisms. The inorganic elements of the 
tissue are first removed by chemical solution produced by the acid-form- 
ing bacteria of the mouth, while the organic material or basis substance 
becomes gangrenous and is afterwards dissolved by the liquefying action 
of the saprophytic micro-organisms and is washed away. 

For more than two thousand three hundred years dental caries has 
formed an interesting subject for medical writers and theorists. 

The etiology of the disease has always furnished a most interesting 
field for original investigation and research, while the peculiarities of 
the physical phenomena presented by the disease and the obscurity of 
the causes which produced them have led to many and divers opinions. 
As a result, several theories have from time to time been advanced to 
explain the phenomena which are manifest in the dissolution of these 
tissues. 

The ancient physicians and dentists who made any attempt to inquire 
into the causes of the affection seemingly contented themselves with offer- 
ing hypotheses more or less ingenious, but based in part upon experience 
and clinical observation, to account for the physical phenomena of the 
disease. No real investigation, however, that could be called scientific 
was at all possible until the invention of the microscope opened the way 
for the study of the histologic structure of the dental tissues, both normal 
and pathologic, and the minute bacterial forms which we now know to be 
the cause of so many diseases. 

History. — It will be interesting to the student to briefly review the 
following theories and trace the evolutionary steps by which the direct 
causes of the disease were finally discovered : 

135 



136 OPERATIVE DENTISTRY. 

1. The Humoral Theory. 

2. The Vital or Inflammatory Theory. 

3. The Worm Theory. 

4. The Putrefaction Theory. 

5. The Chemical Theory. 

6. The Electro-Chemical Theory. 

7. The Germ Theory. 

The Humoral Theory of Caries. — Hippocrates (b.c. 456) and his 
pupils were humoral pathologists. Hippocrates taught that the body con- 
tained four fluid humors, — viz., blood, phlegm, yellow bile, and black 
bile ; that a proper or due proportion of each of these humors constituted 
health, while a disturbance of the proportions resulted in illness. He 
ascribed all diseases to this cause ; hence he and his followers ascribed 
dental caries to a bad condition of the humors, — viz., to the stagnation of 
depraved juices in the teeth. 

This view was generally maintained by physicians for more than a 
thousand years, and is still prevalent in- the traditions of the common 
people. 

Bourdet (1757) still maintained the humoral theory of Hippocrates, 
while most of his contemporaries accepted the vital theory. He claimed 
that when the fluids contained in the vessels of the tooth are too thick 
they coagulate, and since they are confined, putrefy and act directly upon 
the structures of the tooth, producing caries. He also called attention to 
the fact that when a tooth decays, its fellow upon the opposite side of the 
jaw is sooner or later similarly and symmetrically affected, and explains 
this predisposition by the fact that as corresponding teeth are usually cal- 
cified at the same period and pursue the same order of development, so 
the same morbid processes are commonly manifested in the same locations 
of corresponding teeth. 

The Vital or Inflammatory Theory of Caries. — Galen (a.d. 131) 
looked upon dental decay as being caused by a disturbance in the func- 
tions of nutrition. He said, "The lack of nutrition makes the teeth weak, 
thin, and brittle, while an excess of nutrition excites an inflammation very 
similar to that of the soft parts." 

Ambroise Pare (1579), the noted French surgeon, held to the theory of 
the inflammatory nature of dental caries. He says, in discussing the sub- 
ject of toothache, " These organs, after the manner of other bones, suffer 
from inflammation, quickly suppurate, and become rotten." 

Fauchard believed with Galen that caries was caused by vital or in- 
flammatory action, and described seven forms of the disease, — viz., scor- 
butic, variolous, scrofulous, moist or putrid, dry, superficial, and deep ; the 
latter form giving rise to severe pain. He assumed that there must be two 
causes for caries, as for all other diseases of the teeth, one of internal origin, 
producing internal caries; the other external in origin, and producing 
external caries. 

The internal causes, he stated, were referable " generally to the quantity 
and quality of faulty, acrid, or corrosive lymph, which acts upon their 
roots, attacking their external and internal surfaces." The latter doubt- 



DENTAL CARIES. 137 

less referring to the root-canal and pulp-chamber. This variety, he 
stated, was difficult to recognize, from the fact that it is concealed from 
view by the gums and the alveolus. The external causes he does not ex- 
plain, but said these attack the outer portions of the tooth, — viz., the 
enamel, occasionally the neck, and the roots. 

The prevailing opinion of the medical men of this period was that 
caries of the teeth was due to* inflammation, or, in other words, to vital 
action; that it was a true disease of dentin, the term "Odontitis" being 
given to it. Upon this supposition the researches of Fauchard, Bourdet, 
Jourdain, Hunter, Pox, Bell, Cuvier, Duval, Linderer, Meckel, etc., were 
conducted. 

This theory was revived by Newmaim (1862), while Hertz and Abbott 
later attempted to confirm it, but with indifferent success. 

Jourdain (1766) believed with Fauchard in the exclusively vital or 
organic nature of the affection, which was at times inflammatory. 

Hunter (1778) maintained that the disease was a vital process, characterized 
by inflammation and gangrene, and somewhat analogous to caries of bone. 
He said, "It does not arise from internal injury or from menstrua, which 
have the power of dissolving part of a tooth, but we may reasonably sup- 
pose that it is a disease arising originally within the tooth itself." 

He does not, however, seem satisfied with the idea of the analogy be- 
tween the carious process as observed in bone-tissue and in tooth-substance, 
as it does not satisfactorily explain the phenomena of gradual decompo- 
sition and loss of tissue with the formation of cavities. Upon this point 
he says, "The most common disease to which the teeth are exposed is 
such a decay as would appear to deserve the name of mortification. But 
there is something more ; for the simple death of the part would produce 
but little effect, as we find that the teeth are not subject to putrefaction 
after death, and therefore I am apt to suspect that during life there is 
some operation going on that produces a change in the diseased part. It 
almost always begins externally (external caries) in the small part of the 
body of the tooth, and commonly appears first as an opaque white spot. 
This is owing to the enamel losing its regular crystalline texture and being 
reduced to a state of powder from the attraction of cohesion being de- 
stroyed, which produces similar effects to those of powdered crystal. 
When this has crumbled away the bony part of the tooth is exposed, and 
when the disease has attacked this part it generally appears as a brown 
speck." 

He also claimed that occasionally the disease originated in the dentin 
{internal caries), and that in this case the tooth assumed a shining black- 
ness from the dark color being seen through the remaining external shell 
of the tooth, which upon opening is found leading to the pulp-canal. 

Fox (1806) expresses the belief that "the diseases to which the teeth 
are subject have their origin in inflammation." In writing of the proxi- 
mate or direct cause of caries, he considered it to be "an inflammation 
in the bone of the crown of the tooth, which on account of its peculiar 
structure terminates in mortification." This process, he believed, was 
established through inflammation of the dental pulp and lining membrane 



138 OPERATIVE DENTISTRY. 

of the pulp -chamber (membrana eboris). He evidently considered the 
pulp-membrane as analogous to the periosteum, and confounded necrosis 
with caries 5 for he stated that if the inflammation was severe in the pulp- 
membrane, nutrition would be arrested in circumscribed areas, as in peri- 
ostitis, thus causing death of portions of the dentin, which would after- 
wards decompose and form cavities of decay. 

Bell (1831) maintained that dental caries was a species of gangrene, 
and that ''the true proximate cause of dental gangrene was inflammation." 
He did not believe that caries was ever caused by external agencies which 
acted upon the enamel, but was due to internal causes which produced death 
of iDortions of the dentin. He defines dental gangrene as " mortification of 
any part of a tooth, producing gradual decomposition of its substance." 
Further he says, "The situation in which gangrene (caries) invariably 
makes its first appearance is immediately under the enamel, upon the sur- 
face of the bone (dentin)." This, he thought, was explained by the struc- 
ture of the teeth and the nature of the disease. "As the vessels and 
nerves which supply the bone of the teeth are principally derived from 
the internal membrane (pulp), it is natural to conclude that in so dense a 
structure the organization would be less perfect in those parts which are 
farthest removed from its source, and that in the same portion they would 
be less capable of resisting the progress of mortification." With regard to 
the progressive character of the disease, he thought this. could only be ex- 
plained by following the same reasoning. "When a portion of any of 
the other bones loses its vitality it acts as an extraneous body, producing 
irritation in the surrounding parts, and a process of absorption is set up in a 
line of living bone in contact with it in order to effect its separation. A 
similar effort appears to me to be made in gangrene of the teeth, but with 
a very different result, in accordance with the difference in the structure 
of the two seats of the disease. When a portion of the tooth is killed by 
inflammation it excites, as in the other case, an increased action in the 
vessels of the surrounding portion of bone ; but that very action, which in 
such bones as possess greater vital power becomes remedial by promoting 
the removal of the cause of irritation, produces in the present case the 
continued extension of the disease ; for the irritation thus excited, instead 
of effecting the removal of the part by absorption, as in other necrosed 
bones, at once destroys its vitality and renders it only an additional por- 
tion of dead matter to that which had already existed. This, in its turn, 
becomes an extraneous and irritating body to the surrounding bone, in 
which the same action is set up and the same mortification produced, and 
thus portion after portion is successively irritated and killed, until the 
whole crown of the tooth is destroyed." 

Fitch (1829-35), in both editions of his work, expresses substantially 
the same view as did jSTeumann, Hertz, Koecker, and others. 

Koecker says, "Caries of the teeth must be considered as similar to 
gangrene in other parts of the system. And when we speak of caries 
as a disease we mean that diseased action in the bony structure of the 
living tooth produced by chemical irritation of its dead and rotten 
parts. 



DENTAL CARIES. 139 

" Hence it is indispensable that we should make a due distinction be- 
tween caries considered as a disease in the tooth and the effect of that dis- 
ease, — viz., mortification and putrefaction of its whole structure. Caries, 
in fact, is that state of the tooth in which mortification has taken place in 
one part, and inflammation in the part contiguous to it, the former origi- 
nally produced by the latter, and the latter continually kept up by the 
former." 

Koecker, however, maintained that there were two forms of caries, one 
beginning upon the external surface of the tooth, and the other having its 
origin within. The latter variety he looked upon as analogous to an 
abscess of the bone, for he says, "It (the disease) never proceeds so far 
towards the cavity containing the nerves as to render this membrane alto- 
gether unprotected by the bony structure before it has penetrated through 
the external osseous parts, including the enamel, and has thus formed a 
natural outlet for the bony abscess." 

Abbott (1879), Heitzmann, and Boedecker (1886 and 1888) made the 
attempt to revive the vital theory of caries. Abbott describes caries oc- 
curring in a vital tooth as " an inflammatory process, which, beginning as 
a chemical process, in turn reduces the tissues of the tooth into embryonic 
or medullary elements, evidently the same as, during the development of 
the tooth, have shared in its formation ; and its development and inten- 
sity are in direct proportion to the amount of living matter which they 
contain, as compared with other tissues." 

He opposed the idea that micro-organisms in any sense produced 
caries ; that these organisms did not penetrate the basis-substance of the 
tooth, "but appeared only as secondary formations, owing to the decay of 
the medullary elements." 

These authors maintained with the most positive assertions that "there 
occurs a primary inflammation in dentin, independent of pulpitis or peri- 
cementitis, running its course in the middle of the dental tissue, and leading, as 
all inflammatory processes do, either to a new formation or to destruction 
by suppuration." 

They explained the process as follows: "Inflammation causes first a 
solution of the lime-salts, and afterwards a liquefaction of the basis-sub- 
stance, both in bone and dentinal tissue. The result will be the appear- 
ance of globular spaces or bay-like excavations, which exhibit medullary 
corpuscles, or sometimes clear protoplasmic masses corresponding to the 
embryonal stage of the inflamed tissue. . . . By the breaking apart of 
these medullary corpuscles pus may be formed in the middle of the 
dentin, thus representing an abscess independently of the pulp-tissue ; 
or, on the other hand, a healing process may take place through the 
redeposition of lime-salts." These- views were never adopted by the pro- 
fession in general, as they were based upon alleged facts which were 
entirely foreign to the teaching of the best authorities in morphology, 
histology, and pathology, and, furthermore, others were not able to demon- 
strate them. 

The Worm Theory of Caries. — Just when or by whom the theory 
that worms were an essential factor in the origin and development of 



140 OPERATIVE DENTISTRY. 

caries is not known, but it is certain that for many centuries they were 
regarded as the cause of the disease, and various remedies were employed 
to destrojr them or drive them out. Scribonius used fumigations, Ebu- 
Sina emixLoyed the seeds of henbane, leek, and onions. Musetanus (1114), 
Krautermann (1732), Euyleman (1824), Kremler, and many others recom- 
mended similar measures. (Miller.) 

Whether this theory arose as the result of imperfect observation or 
from a deliberate intention to deceive, history does not enlighten us. The 
chances are, however, that it was invented by some charlatan who desired 
to defraud the public and thereby fill his purse. This theory is commonly 
believed in China at the present day, and their dentists pretend to remove 
such parasites from the teeth. The worms, which are artificial, are dex- 
terously placed in the mouth of the patient by the dentist during his 
manipulations, and then extracted and held up to the gaze of the wonder- 
ing but satisfied victim. 

Fauchard (1728) took infinite pains to discover the worms which were 
supposed to be the cause of the disease, and the odontalgia which was a 
frequent accompaniment of the disintegration of the tooth, but failed to 
discover them either in the carious dentin or in the salivary calculus. 

Pfaff (1756) discovered worms in the mouths of persons who ate decay- 
ing cheese, but he was ' ' not able to observe that these worms had pro- 
duced toothache by gnawing." (Miller.) 

The Putrefaction Theory of Caries.— Pfaff (1756) was the first to 
advance the theory that dental caries was caused by putrefaction. He 
says, "Remains of food which undergo putrefaction between the teeth 
occasion decay of the teeth." 

Ficinus (1847) attributed dental caries to a putrefaction induced by 
certain minute infusorial animalcules which live in the mouth, and to 
which he gave the name Denticola. He believed these organisms produced 
a kind of putrefaction which first attacked the enamel cuticle, then pro- 
ceeded to destroy the enamel, and afterwards the dentin. The process of 
putrefaction requires an alkaline reaction, but he does not explain the dis- 
appearance of the calcium salts, which require acids for their solution. 
(Leber and Eottenstein.) 

Klencke (1850) maintained the theory of putrefaction as the cause of 
caries, but divided caries into two distinct varieties, — central caries and 
peripheric caries. The former, he stated, has its origin in the pulp-cavity, 
the latter in the external portions of the teeth. 

Peripheric caries he divided into three different forms : 

1. Soft caries (caries acuta), caused by the agencies of putrefaction, 
dental animalcula, denticole hominis. 

2. A soft caries (caries acuta), due to the proliferation of a vegetable 
parasite called Protococcus dentalis. 

3. The so-called dry caries (caries chronica), in which the parasites 
have no part ; this form being caused by the chemical action of acids upon 
the dental tissues. 

The Chemical Theory of Caries. — For many years, and up to a 
very recent period, the acid theory of decay received the support of a large 



DENTAL CARIES. 141 

majority of the profession. In fact, it was the prevailing theory until the 
researches of Miller proved the disease to be caused by the zymogenic 
bacteria. 

Many of the advocates of the "acid theory" taught that the teeth 
when once formed were not susceptible to change in structure, and that 
consequently they were passive in the hands of the disease ; that the cause 
of caries was a purely chemical one, based upon the known fact of the 
affinity of acids for calcium salts. 

Although the chemical theory may be said to be of modern origin, it 
nevertheless received its first suggestions from some of the older writers. 
According to Miller, Paul, of iEgina (636), first suggested the idea that 
acids might cause caries. He says, "In order to preserve the teeth pre- 
cautions should be taken against the spoiling of food in the stomach, 
since the frequent vomiting resulting from it is very injurious to the 
teeth." 

Carabelli is authority for the statement that the first experiments in 
regard to the action of acids upon the teeth were made by Berdmore (1771) 
with nitric and sulphuric acids. Pasch (1767), Bucking (1782), Becker 
(1808), and Eingelmann (1824) all attributed injurious effects to some 
foods and acids. (Miller. ) 

Harris (1830) was the first writer to announce his belief that caries 
was caused by a purely chemical process, the result of the action of acids 
within the mouth acting upon the calcareous material of the tissues of the 
tooth. 

Robertson (1835) combated the vital or inflammatory theory of the 
disease, and stated that caries was caused by a chemical decomposition of 
the dental tissues by the means of acids, the acids being formed in the 
mouth by the dissolution of food particles. 

Linderer (1837) considered caries to be due to a purely chemical 
process induced by the oral fluids, and combated the inflammation theory, 
for, ' ' since dentin contains no blood-vessels, inflammation in this tissue is 
not conceivable." He also denied the existence of the so-called internal 
caries. 

Eegnaud (1838) upheld the pure chemical theory of caries, considering 
the disease to be the result of the destruction of the dental tissues by 
acids formed within the mouth. He further stated that silk ligatures 
wound around the teeth, when left for a considerable period, cause the 
destruction of the enamel, while caps covering the teeth, whether made 
of wax or some metallic substance, promote their destruction, and human 
teeth, artificial sets, and individual teeth made from ivory also undergo 
destruction. 

Westcott (1843) proved conclusively by a long series of experiments 
that acids, both vegetable and mineral, act more or less vigorously upon 
the calcified structures of the teeth. 

Allport, a few years later, conducted a similar series of experiments 
with the vegetable and mineral acids, and arrived at substantially the 
same conclusions. 

Desirabode (1846) recognized two forms of caries, one external, which 



142 OPERATIVE DENTISTRY. 

is caused by a chemical destruction acting from without inward, and the 
other internal, arising from some injury to the pulp or from a congenital 
defect in the dentin and developed spontaneously from within outward. 

Tomes (1837) was contemporary with Eobertson, and in his earlier 
writings his views were quite similar to those of Klencke. In his later 
work (1873) he concluded that caries was the effect of external causes in 
which the so-called vital forces play no part ; that it is due to the solvent 
notion of acids which have been generated by fermentation going on in 
the mouth, the buccal mucus probably playing no small part in the matter ; 
and when once the disintegration is established in some congenitally de- 
fective point, the accumulation of food and secretions in the oral cavity 
will intensify the mischief by furnishing new supplies of acids. In his 
third edition he states that the buccal organisms have no small share in 
the matter of causing the disease. 

Tomes was the first to accurately describe the histologic alterations 
which take place at the seat of caries. These changes in the enamel he 
thought were caused in the majority of cases by imperfect development, 
with a greater porosity of the tissues, the porosity increasing with the 
progress of the disease. The most remarkable changes were found in the 
canaliculi of the dentin. In cross-section they were seen to be surrounded 
by a thickened sheath, having a tobacco-pipe-stemmed appearance. In 
completely decalcified dentin the canaliculi with their enclosed soft fibrils 
— Tomes' s fibrils — remain free in the softened mass. In the more advanced 
stage of the disease he found these elements losing the sharpness of their 
contour and assuming a finely granular appearance. When the progress 
of the disease was very rapid, the dentinal sheaths presented varicosities 
and globular swellings. 

These pathologic changes proceed along the canaliculi towards the 
pulp, giving usually to the carious or infected portion of the dentin the 
form of a brownish cone with its base turned towards the enamel. In 
those cases in which a more extended surface of the enamel was involved, 
and where the destructive process was rapid, the cone existed only incom- 
pletely or was entirely wanting. Around the cone of discolored dentin a 
zone of relative transparency existed in which the canaliculi contained 
calcined dentinal fibrils. 

These changes were attributed by Tomes to organic or vital reaction of 
the dentin against the pathologic irritation induced by the caries, and he 
believed retarded or arrested the progress of the disease. 

Oudet (1862) described two distinct forms of caries, — viz., external and 
internal. The former he believed to be caused by the action of acids upon 
the inorganic elements of the tooth, while the latter was the result of in- 
flammatory action occurring within the substance of the dentin, which 
secondarily involved the contiguous portion of enamel. 

Watt was perhaps the most conspicuous and aggressive advocate of the 
purely chemical theory of dental caries. He maintained that caries was 
caused by mineral acids principally, though he did not exclude the action 
of the organic acids, and insisted that the different colors seen in caries 
was the result of the action of these mineral acids, — viz., nitric, pro- 



DENTAL CARIES. 143 

ducing white decay ; sulphuric, black decay ; and chlorohydric, the 
intermediate colors. 

Taft in his earlier writings favored the chemical theory of caries. In 
his opinion, "acid mucus and saliva, vitiated secretions, products of de- 
composition of animal and vegetable matter in the mouth, galvanic action, 
and mineral and vegetable acids, were the chief causes of dental decay." 

Schenckler believed most strenuously that acids produced caries, for he 
says, "Be it repeated, where there is no acid no caries is possible." 

Baume stoutly maintained the correctness of the chemical theory, and 
as strongly opposed the parasitic theory. He said, "The fungi are the 
result of the caries." 11 

Magitot (1867), in his "Treatise upon Dental Caries," advocated the 
purely chemical theory of caries, claiming that the disease was caused by 
the acids contained in the saliva, or formed in the mouth by fermentation. 
He states as his conclusions, reached after a long series of observations and 
experiments upon natural teeth and those carved from ivory, under both 
natural and artificial conditions : 1. That dental caries is a purely, chemi- 
cal alteration of the enamel and dentin. 2. That the disease always 
progresses from the external surface of the organ inward, attacking first 
the enamel, second the dentin, and third the pulp, and that the existence 
of internal caries cannot be fairly proved. 3. Disorganization of the 
enamel is a purely passive chemical process. 4. That in vital teeth there 
is developed between the caries of the dentin and the pulp a "cone or 
white zone formed by a mass of canaliculi obliterated in consequence of a 
formation of secondary dentin." This he terms the cone of resistance, and 
looks upon it as an effort of nature to resist or retard the progress of the 
disease. 5. That artificially produced caries presents the same phenom- 
ena as natural caries, with the exception of the evidences of organic or 
vital resistance. 

The Electro-Chemical Theory. — This theory was promulgated by 
Bridgman (1861-63), and endorsed by the Odontological Society of London. 

The discovery by Faraday of the simple galvanic battery — viz., that a 
copper or zinc rod, with one end immersed in a dilute solution of sulphuric 
acid in water and the other exposed to the atmosphere, soon became polar- 
ized, and that at a point on the rod corresponding to the surface of the 
liquid the metal was gradually eroded and the material carried up the 
rod and deposited upon the portion exposed to the atmosphere, the acid 
forming one element of the battery, and the oxygen of the atmosphere 
the other — suggested to the mind of Bridgman that here, perhaps, was 
the solution of the vexed question of the cause of dental caries. He there- 
upon instituted a series of experiments upon teeth out of the mouth under 
conditions as nearly like those obtaining within the mouth as he could 
compass, with the result of producing caries artificially, which in appear 
ance was identical with that produced out of the mouth by acids, and in 
general features corresponded to the microscopic appearance of natural 
caries. 

He argued from this, applying the principles involved in the discovery 
of Faraday, that a tooth in the living body was always polarized, and had 



144 OPERATIVE DENTISTRY. 

well-established electric currents, that the root of the tooth when invested 
with the gum and alveolus, like the end of the rod immersed in the 
dilute sulphuric acid, possessed electro-positive qualities, while the crown 
of the tooth, like the free end of the rod, being exposed to the atmos- 
phere, had electro -negative qualities, consequently each tooth was a minia- 
ture galvanic battery, and whenever fluid or moist pulpy material was 
permitted to remain undisturbed in one position, as in the sulci and 
approximal spaces, for a few hours, the electric currents, which are con- 
stant, decompose them, and as a result acids are formed which attack the 
lime-salts of the tooth, and caries is established. 

He further claimed that the insertion of metal plugs within the teeth 
increased the galvanic action and also accounted for secondary caries. 

Palmer, Chase, and Flagg endorsed the views of Bridgman in reference 
to the production of secondary caries, and became the sponsors of what is 
known as the New Departure Theory in relation to the relative values of 
the various filling-materials as conservers of tooth-structure. These 
gentlemen instituted a long line of experiments to establish the position, 
in the electro-chemical series, of dentin with the various filling-materials. 
These experiments resulted in the demonstration of the following scale : 
Electro-negative : gold ; amalgam, tin, gutta-percha, dentin, oxychloride 
of zinc -f electro-positive. 

The strongest electro- motive force or electric action is therefore gen- 
erated by a combination of gold and dentin, and in a decreasing ratio 
amalgam and dentin, tin and dentin, gutta-percha and dentin. Palmer 
claimed that these materials in the order named above possessed a com- 
patibility with tooth-structure iu an increasing ratio, — viz., gold being the 
least compatible, and the ratio increasing to the bottom of the list. 

These authors and their followers have, claimed further that the varia- 
bility in the structure of the teeth plays an important part in the liability 
to secondary caries ; teeth of low organization — "of greater porosity" — 
furnishing the most favorable conditions for a recurrence of the disease 
after the tooth had been filled, and those of the highest organization offering 
the least favorable conditions. Moisture is necessary in order to establish 
galvanic action between the filling- material and the dentin. This moisture 
is furnished by the fluids of the mouth which act at the margins of the 
filling, but it has been claimed that the tooth itself also furnishes moisture 
through its tubuli which in teeth of low organization would be sufficient 
to establish galvanic currents between the tooth and the filling- material, 
followed by decomposition of the fluid, the formation or liberation of 
acids, and decalcification of tooth-structure. 

The Germ Theory. — In discussing the various relations of micro- 
organisms to the process of fermentation, it has been frequently suggested 
that caries of the teeth might be, in part at least, caused by the action of 
micro-organisms. 

Erdl (1845) was the first to definitely state that dental caries was caused 
by parasites. These, he claimed, formed upon the crown as a delicate, 
colorless membrane, composed of cells, which later became more irregular 
aad their nuclei more distinct. Miller thinks that inasmuch as Erdl em- 



DENTAL CARIES. 145 

ployed muriatic acid to isolate the " caries matter," that it is quite prob- 
able that the delicate membrane which he obtained was nothing more than 
ISTasmyth's membrane. Ercll applied creosote and nitric acid to destroy 
the parasites and prevent the progress of the disease. His method was 
first to apply creosote until the " caries matter" was impregnated with it, 
then nitric acid, the latter immediately producing a violent and complete 
decomposition of the creosote and of the parasites saturated with it. 

Ficinus, in 1847, suggested, as we have already seen, that the organisms 
of putrefaction — his denticolce — were the active agencies which produced 
the disease. These, he claimed, proliferated in IsTasmyth's membrane, 
which they destroyed ; they next attacked the material between the enamel 
prisms, thus deconrposing this structure and penetrating the dentin, which 
they destroyed in the same manner. 

Klencke (1850) discovered another parasite in the human mouth, which 
he denominated protococcus dentalis, and claimed that this fungus possessed 
the power of liquefying enamel and dentin. He says of it that it "softens 
and destroys dental substances, and is nourished by their chemical 
elements. ' ' 

The first extended study of the organisms which are found in the mouth 
was undertaken by Leber and Rottenstein, and the results of their labors 
were published in 1867. These authors believed that there were two forms 
of caries, one which they denominated central caries, having its origin in 
the cavity of the pulp, but an exceedingly rare form, and another to which 
is applied the term external caries, having its origin in the enamel, and 
caused by external influences. 

In reference to central caries, they presented a single case in illustra- 
tion, in which three teeth (two superior and one inferior incisor) in the 
mouth of a lady twenty-one years of age had lost their vitality from a 
traumatism, — a fall in early childhood. The teeth were blue in color, but 
there was no evidence of caries having penetrated from the surface. "In 
piercing the posterior face of one of these teeth it was found completely 
softened, even to the enamel, and the tissues had a brown color. The root 
itself was hollowed to a considerable extent. The same was found to be 
the case with one of the other teeth. The third, whose color was not so 
marked, and which caused no unpleasant sensation, was let alone." 

Microscopic examination was not possible, hence doubt must exist in 
relation to the supposition that caries did not originate from some micro- 
scopic defect in the enamel. 

These authors do not attempt to explain the cause which produced the 
central caries (?), but say, ' ' We believe that there exist cases where the 
dental tissues are attacked and destroyed from the cavity of the pulp ; but 
these cases are extremely rare, and the conditions of their production are 
not yet well understood, except, perhaps, the previously necessary death 
of the tooth. ' ' 

With regard to external caries, they were of the opinion that the disease 
commences as a purely chemical process, but that as soon as the enamel is 
dissolved and the surface of the dentin exposed the elements of the lepto- 
thrix buccalis enter and penetrate the dental canaliculi, enlarging them, 

10 



146 OPERATIVE DENTISTRY. 

and thus increasing the facilities for the penetration of the acids which 
dissolve the lime-salts. 

Weil (1880), writing in support of Leber and Rottenstein' s view of 
caries, says, " Decay generally begins from without, and must, therefore, 
first make its way through the enamel-cuticle. 

"It is highly probable that the fungus (leptothrix buccalis) bores 
directly through it. The fungi now proceed farther into the enamel, and 
force its prisms apart, gradually disorganizing its structure. From the 
enamel they penetrate into the tubules of the dentin, which are often en- 
larged by them to two or three times their original size, at the same time 
dissolving the calcium salts." 

Arkovy stated the disease was " brought about by chemical action, in 
which the invasion of nosogenous fungi play an essential part." 

Milles and Underwood, in a paper presented to the International 
Medical Congress, held in London in 1881, gave new interest to the germ 
theory of dental caries, and marked the most important advance made in 
the discovery of the causes of the disease up to this time. 

The work of Leber and Rottenstein had found but few advocates, and 
had only stirred a passing interest in the subject, as the profession in 
general seemed satisfied with the acid theory of the disease. 

The marked success, however, of Lister (1865-69) in the treatment of 
wounds, which was based upon the discoveries of Pasteur in relation to 
the organisms of the various ferments, added new interest, and stimulated 
investigation into the theory advanced by Leber and Rottenstein of the 
etiology of dental caries. 

Koch (1881) added greatly to the facilities for observing these micro- 
organisms by the introduction of his improved methods of staining, and 
made it possible for later investigators to escape the errors into which 
their predecessors had fallen. 

Milles and Underwood, noticing the constant presence of micro- 
organisms in decaying dentin, and the equally constant enlargement of 
the dentinal tubuli, came to the conclusion that in the process of dental 
decay "two factors were always in operation,— first, the action of acids, 
and second, the action of germs. 

This theory, which, for the sake of distinction, may be called the septic, 
is rather an amplification of the chemical theory than a contradiction of it. 

They say, ' i Most probably the work of decalcification is entirely per- 
formed by the action of acids, but these acids are, we think, secreted by 
the germs themselves, and the organic fibrils upon which the organisms 
feed, and in which they multiply, are the scene of the manufacture of their 
characteristic acids, which in turn decalcify the matrix and discolor the 
whole mass." 

In reference to caries of cementum they say, "From our observations 
on cementum to which caries has extended, we conclude that the process is 
very similar ; the bioplasmic contents of the lacunse and canaliculi afford 
food and lodging for the organisms, which multiply, and when sufficiently, 
numerous decalcify the surrounding bone so that each lacuna loses its out- 
line and extends in all directions." 



DENTAL CARIES. 147 

Miller (1882) announced the results of a series of experiments which 
he had conducted in relation to the active causes of dental caries, that it 
was his opinion that the first stage of the disease consisted of a decalcifica- 
tion of the tissues of the teeth by acids which are, for the greater part, 
generated in the mouth by fermentation. In this he agrees with Leber 
and Bottenstein, and partially with Milles and Underwood. 

In his later studies, which were published in the Independent Prac- 
titioner, 1884 and 1885, he carried the subject much farther, and arrived at 
conclusions which have been generally accepted, and now form the basis 
of the present teaching upon this subject. 

He says, in summarizing his work (1884), — 

"1. I convinced myself by the examination of some thousands of 
slides of carious dentin that micro-organisms were always present, and that 
they, without any doubt, were the cause of various anatomical changes 
which were found to take place in the structure of the dentin during 
caries. (Here, of course, the question of priority does not suggest itself ; 
Leber and Bottenstein, as is well known, were the first to give definite 
expression to this fact, ) 

"2. I proved, at the same time, that the invasion of micro-organisms 
was not, in the large majority of cases, simultaneous with the softening 
of the dentin, but that large areas of softened dentin could be found that 
contained no fungi. 

' ' Of all those who examined my preparations in America, no one, what- 
ever his theory, ever once denied this fact. I concluded from this that the 
softening of the dentin went in advance of the invasion of the organisms. 

" 3. I determined, by analysis of masses of carious dentin sufficiently large 
to give reliable results, that the softening of the dentin is of the nature of a 
true decalcification ; that the decalcification of the outer layers is almost 
complete and diminishes in degree as we advance towards the normal 
dentin ; furthermore, that the same relations maintain in dentin softened 
in a mixture of saliva and bread, or in weak organic acids ; also, that in a 
mass of carious dentin the lime-salts had been removed to a much greater 
extent than the organic matter. 

u 4. I maintained from the first that the softening of the dentin was 
produced by acids for the most part, generated in the mouth by fermenta- 
tion. I had, however, no proof of this. 

" 5. I proved that fungi exist in great numbers in the human saliva and 
in carious dentin, which have the power to produce acid under conditions 
which are constantly present in the human mouth. I determined this acid 
— for one of the fungi at least — to be the ordinary ferment, lactic acid. 

Ci 6. I produced caries artificially, which under the microscope cannot 
be distinguished from natural caries, by subjecting sound dentin to the 
action of these fungi in these fermentable solutions. 

"7. I determined the influence of various antiseptics and filling mate- 
rials upon the fungi of caries. 

" 8. I isolated various forms of these fungi, and determined, in part, 
the conditions most favorable to their development, their characteristic re- 
action upon gelatin, their physiologic action, their effect when inoculated 



148 OPERATIVE DENTISTRY. 

into the system of lower animals, and their possible connection with 
certain obscure diseases generally attributed to the carelessness of the 
dentist,'' 

J. Sim Wallace * (1899) contends that caries is in no wise an inherited 
affection, nor is heredity a predisposing factor, but that certain inherited 
peculiarities of the teeth might favor the lodgement of food and micro- 
organisms and thus predispose to caries ; and that the environment of the 
teeth and consequent liability to caries is similar in certain families and 
races, on account of the similarity in diet and other customs. 

An important factor in the predisposition to caries lies in the relative 
lodgeability of the various food-stuffs. He believes the fibrous food-stuffs 
have a detergent action upon caries, in that these foods are less liable to acid 
fermentation. Comparing the conditions of the mouth following a meal 
made from flesh of any kind and that following a meal made from starchy 
foods, a marked difference is noticed in their relative cleanliness. In the 
former the mouth is comparatively clean, only a few fibres remaining 
between the teeth, and these easily removed, while in the latter the inter- 
approximal spaces and the fissures of the teeth are packed full of fer- 
mentable material, which is difficult to thoroughly remove, and thus are 
established all the conditions which are most favorable for the production 
of lactic acid fermentation and the decay of the teeth. 

Mouth-Bacteria and Carbohydrates. — The chief source of nourish- 
ment for micro-organisms in the human mouth, according to Miller, is 
furnished by two groups of substances, the carbohydrates and the albu- 
minoid substances. These are almost constantly found in the human 
mouth, either in the sulci and fissures of the teeth, in the approximal 
spaces, or upon their free surfaces. These substances are readily acted 
upon by the zymogenic and saprogenic bacteria. In all forms of fermen- 
tation there is a limit under ordinary circumstances to the quantity of the 
waste products produced by zymogenic bacteria. 

Black states : "It is an established law that the waste products of an 
organism become poisonous to that organism when they have collected in 
a certain quantity. This is true of urea in the animal, it is true of alco- 
hol in the vinous fermentation, and Miller found it to be true of the 
organism causing caries. When lactic acid has accumulated in certain 
quantity (this amount not yet definitely determiued) the further develop- 
ment of the organism is interfered with. Their power to go on producing 
lactic acid in the depths of the dentin is accounted for by the formation, 
from the lime-salts of the tooth, of the lactate of lime, which does not in- 
terfere with the further development, and, in fact, is equivalent to a removal 
of the waste product. Long before the existence of a special organism in 
lactic fermentation was known, it had been found that by adding chalk or 
other form of lime the fermentation could be continued and much more 
lactic acid produced. Following up these facts, Miller has analyzed 
carious dentin and found it to contain calcium lactate. ' ' 

From the foregoing facts the student will readily understand why, as a 

* The Cause and Prevention of Decay in Teeth. 



DENTAL CARIES. 149 

rule, dental caries when once established steadily progresses — more or less 
rapidly — until the tooth is completely destroyed. 

Were it not for the presence of the calcium in the structures of the 
tooth with which the lactic acid combines, forming lactate of calcium, the 
waste product of the organism — lactic acid — would soon destroy the bac- 
terium, and the progress of the disease would be arrested. 

The carbohydrates in undergoing fermentation produce an acid reac- 
tion, while the decomposition or putrefaction of the albuminoid sub- 
stances present an alkaline reaction. When these substances are mixed 
they are, as a rule, accompanied by an acid reaction. Consequently the 
reaction from the fermentation of food debris — which is usually composed 
of carbohydrates and albuminoids — will be found most often to give an acid 
reaction. This, however, is not an invariable rule, for Miller found that 
the reaction depended partly upon the nature of the food found in a par- 
ticular part of the mouth at the time and partly upon the particular kind 
of bacterium which was acting upon it. 

In the case of one bacterium which he examined in reference to this 
question, he found that when it was cultivated in a three per cent, solution 
of beef extract, in the presence of one-tenth per cent, of sugar, it gave a 
neutral reaction, but upon increasing the amount of sugar the reaction 
became acid, and upon diminishing it the reaction became alkaline. 

Miller, in another series of experiments instituted to determine the 
action of the mouth bacteria upon the carbohydrates, found that out of 
twenty-two varieties, sixteen in a very short time produced an acid re- 
action when cultivated in beef extract, peptone-sugar solutions ; four under 
the same conditions gave an alkaline reaction, while in only two did the 
reaction remain neutral. 

Following this with another series of experiments with twenty-five 
mouth-bacteria, thirteen stomach -bacteria, and fourteen intestinal bac- 
teria, instituted for the same jmrpose, sixteen of the mouth-bacteria gave 
an acid reaction, four alkaline, and five inconstant results ; of the thirteen 
stomach-bacteria, nine produced an acid reaction, two alkaline, and two 
inconstant results ; of the fourteen intestinal bacteria, six gave an acid 
reaction, five alkaline, and three inconstant results. Miller, in his next 
series of experiments, undertook the task of demonstrating by qualitative 
analysis the character of the acids formed by the acid producing mouth- 
bacteria. It was generally believed up to this time that the lactic acid 
fermentation could not be brought about except in the presence of one 
specific micro-organism, — viz., the bacterium acidi lactici. Miller had dis- 
covered, however, some time previously, that several forms of bacteria 
found in the human mouth were capable of forming lactic acid out of 
sugar. This discovery has since been verified and established by various 
investigators, as well as the fact that a large number of bacteria are pos- 
sessed of inverting and peptonizing properties. 

Out of eighteen different forms of acid producing bacteria, Miller found as 
a result of his labors that ten of them produced lactic acid. Among the 
other products of fermentation of these bacteria were formic, acetic, and 
butyric acids, "the latter, however, in very small quantities." 



150 OPERATIVE DENTISTRY. 

Lactic acid, however, requires for its production in the mouth, — 

1. Substances which are capable of being converted into glucose, 
C 3 H 12 6 , — viz., the three groups of carbohydrates, — glucoses, C ti H 1L ,0 6 ; sac- 
charoses, C n TL 22 O u ; and ankyloses, C 6 H 10 O 5 . 

The carbohydrates of the glucose group which are most common in the 
food of human beings are grape-sugar (dextrose) and fruit-sugar (levulose), 
cane-sugar of the saccharose group, and starch, cellulose, and gum in the 
amylose group. 

• Hydration converts grape-sugar into two fermentable substances, levu- 
lose and dextrose, their chemical composition being the same, CgHjoOg. 
This change is brought about by the action of such organized ferments as 
ptyalin and amylopsin. The conversion of starch into glucose is repre- 
sented by the following formula : C 6 H kA + H P = C 6 H 12 6 . 

J Starch. Glucose. 

2. The fermentable carbohydrates must be acted upon by ferments 
capable of converting these substances into lactic acid. These ferments 
are constantly found in the human mouth in the form of various zymo- 
genic bacteria, while the necessary conditions for their growth and devel- 
opment — heat and moisture — are ever present. 

The fungi have the power to cause the sugar to split up without the 
formation of carbon dioxide, a molecule of glucose, C 6 H 12 6 , forming two 
molecules of lactic acid, 2C 3 H 6 3 . 

It is noticeable, however, that caries does not always progress with 
the same rapidity in the same individual or in different individuals ; that 
the character of the disease is not always the same ; that certain teeth 
are attacked, to the exclusion of others, while there is a marked differ- 
ence in the extent of the disease between individuals and in the same 
individual at different periods of life, and under varying conditions of 
health. 

The question very naturally arises as to the cause or causes for these 
differences. Are they due to the degree of vital resistance possessed by the indi- 
vidual at the time, or by individual teeth ? Or are there conditions operative 
within the mouth which favor the growth of the lactic acid producing ferments 
at one time and retarding them at another f It is not at all improbable that 
in the multitude of mouth-bacteria some form inimical to the growth of 
lactic acid forming organisms may under certain conditions gain the as- 
cendency for a time, and thus in a measure control the production of the 
lactic acid ferment. The further study of these organisms may yet dis- 
cover such a bacterium which, introduced into the mouth, will retard or 
prevent the growth of lactic ferments, and thus solve the problem of the 
prophylaxis of dental caries. 

The tendency to caries is always augmented in certain forms of disease, 
like the continued fevers, tuberculosis, anseniia, and all wasting affections. 
These abnormal conditions of health not only reduce the vital resistance 
of the general system and lower the vis naturae of individual tissue, but 
they produce abnormal conditions of the buccal secretions which favor the 
growth of the zymogenic mouth-bacteria. It is therefore possible that both 
of these factors act together under the conditions indicated, not only to in- 



DENTAL CARIES. 151 

crease the tendency to caries, but also the extent of the disease and the 
rapidity of its progress. 

Mouth-Bacteria and Albuminoids. — It is generally recognized at 
the present time that a great number of the bacterial forms possess the 
power of liquefying, digesting, or peptonizing coagulated albumin and 
collagen, which forms the basis substance of dentin and bone. 

Miller says, "By far the majority of mouth bacteria, in fact, of all bac- 
teria, possess an action similar to pepsin, in converting coagulated albu- 
min into soluble modifications." The bacteria possess the power of pep- 
tonizing these substances in either an acid, alkaline, or neutral medium, 
while pepsin acts only in the presence of acids, preferably hydrochloric. 
Albuminoid substances are, therefore, excellent media upon which to 
cultivate bacteria. 

Miller found the products of mouth bacteria cultivated upon albu- 
minoid substances to be the same as those developed from the putrefaction 
of organic substances in general. 

These are principally malodorous and noxious gases — sulphuretted 
hydrogen (H.,S), ammonia (KEL), carbon dioxide (C0 2 ) — and numerous 
substances, such as formic, acetic, butyric, valeric, and other acids. 

He also found that four of the mouth bacteria which he examined 
would not grow upon coagulated albumin ; six had but a limited growth, 
while all the others " developed comparatively well, in some cases com- 
pletely liquefying the albumin." 

It will thus be seen that the mouth bacteria are capable of producing 
dental caries, that certain of them possess the necessary j)roperties for 
forming acids, which, acting upon the lime-salts of the enamel, disinte- 
grate this tissue and thus permit the entrance of these organisms into the 
dentinal tubuli, where they continue the process by dissolving or abstract- 
ing the lime-salts from the dentin, and that afterwards certain other forms 
liquefy, peptonize, or digest the basis substance, thus removing the organic 
tissue and forming a cavity of decay. 

Bastyr (1885), in commenting upon the active causes of dental caries, 
says. '• As long as it cannot be shown that the appearances observed in the 
decay of living teeth, decay of dead (pulpless) teeth in the mouth, and 
artificial caries show any appreciable differences, so loug will every 
attempt to explain decay as a vital process be very difficult." 

Black (1886), in discussing the germ theory of caries as promulgated 
by Miller, says, "The fungus has no power of attacking anything, or 
growing into anything, except it be a thing that offers spaces filled with 
soft tissue, or openings into which it may grow as the vine grows through 
spaces in a lattice- work. 

"It is not the organism that makes the attack, but the products of the 
organism, the lactic acid. 

' ' When the dental tubules are once exposed, they form a protection 
to those filaments of the fungus which strike into them in the process of 
growth, and development occurs in that direction. Hence the continuous 
progress of caries when it has once fairly begun in the dentin. Then the 
growth will continue in any direction in which space is offered for the 



152 OPERATIVE DENTISTRY. 

development of filaments. In this way the tubules become packed full 
of the organisms, and the surrounding dentin is always decalcified in 
advance of the growth of the fungus by the lactic acid produced. That 
this is the true explanation of the etiology of dental caries there is no 
longer a reasonable doubt." 

Gysi (1887), in writing upon the chemico-parasitic theory of caries, 
remarks, "As all my experiments and investigations upon this subject 
have presented facts which are consistent with it, I accept it as a satisfac- 
tory explanation of the etiology of the disease." 

Pierce (1888) endorsed this theory in the following words : "I am a 
firm believer in the fact that dental caries cannot progress without these 
low forms of life." 

Sudduth (1888) says, "Dr, Miller's theory of the formation of cavities 
by the action of a digestive fermeut upon the basis substance of dentin 
has been the only theory ever advanced that explained the formation of 
cavities." 

Allan (1889) maintains that "the germ theory is the only one so far 
presented that clearly and satisfactorily accounts for the acid," and, fur- 
ther, that ' ' the ' germ theory' fully explains the distended tubules and 
the broken-down basis substance." 

Caries of the Enamel. — Up to a very recent period our knowledge 
of the phenomena of caries of the enamel has been very meagre. 

Miller, in his earlier descriptions of the phenomena, etiology, and 
morbid anatomy of dental caries, did not give a very clear and distinct 
idea of the modus operandi of caries in the enamel, but his later sug- 
gestions and observations, correctly interpreted, led the way to the more 
definite discoveries of Williams in the morphology and histologic anatomy 
of the enamel, described in Chapter III., Histology of the Dental Tissues, 
to which the student is referred. 

Williams (1898) found, in studying enamel structures, that in decalci- 
fying sections of fully formed enamel the acid attacks the interprismatic 
substance first, and the rods fall apart, proving conclusively that the sub- 
stance is one which is acted upon by acids, — viz., calcareous material, and 
not an organic basis substance composed of animal matter, but more readily 
acted upon than the enamel-rods themselves. If the process of decalcification 
was continued, the enamel-rods were attacked and the whole structure 
destroyed, leaving behind no evidence whatever of an organic matrix. 

Sections of enamel treated by a one per cent, solution of chromic acid 
— which does not destroy organic substances — left no trace of organic ma- 
terial ; hence it can be positively stated that fully developed enamel con- 
tains not the slightest evidence of an organic matrix. 

Williams, in his studies of caries of enamel, found zooglcea masses of 
micro-organisms adherent to the surface of the enamel, probably attached 
to the remains of the enamel cuticle and lining the surfaces of the cavities 
of decay. He says, "Lining the cavities or covering the surface where 
decay has commenced, there is always to be seen a thick, felt-like mass 
of acid-forming micro-organisms. This mass of fungi is so dense and 
adhesive as to make it highly improbable that the enamel is affected, 



DENTAL CARIES. 153 

except in rare or special instances, by any acid other than that which is 
being excreted (lactic) by the bacteria at the very point where they are 
attached to the enamel. This thick, glutinous-like mass of fungi also 
prevents the excreted acid from being washed away, so that it exerts its 
full chemical power upon calcified tissue." This idea was first suggested 
by Ficinus as far back as 1847. 

Dilute lactic acid produced appearances upon sections of fully formed 
enamel that were identical with those produced upon this tissue in the 
progress of natural caries. 

Decalcification of the enamel proceeds most rapidly along the line of 
the enamel-rods when the process has once been established. The bac- 
teria growing into the spaces formed by the solution of the interprismatic 
cement substance cause fracture and dislodgement of masses of partially 
decalcified enamel-rods, and thus hasten the process of cavity formation. 

In cases of rapid caries, Williams found streptococci almost always 
present, while in caries of slow progress ("backward decay") the large 
cocci and diplococci were always found. In the direct caries of enamel 
the cavities are lined with leptothrix and thread-like forms. 

The leptothrix Buccalis maxima and the bacillus Buccalis maximus of 
Miller are nearly always found, the latter more sparingly. 

Beneath the felt-like masses of thread-forms, and lying in contact with 
the decomposing enamel in direct decay, and also in deep cracks and fis- 
sures in backward decay, there is invariably found a short, thick bacillus, 
usually constricted in the centre. 

Williams suggests that possibly the variety of the organism found in 
these forms of enamel decay may be the governing factors in the rapidity 
of the progress with which dissolution of the enamel takes place. 

In the light of these discoveries it may be stated with certainty that 
the first stage of dental decay is characterized by a softening of the 
enamel, which is brought about as a direct result of the presence of carbo- 
hydrates which undergo fermentation through the action of certain zymo- 
genic bacteria, and that these organisms are retained in protected positions 
through the formation of a gelatin-like substance secreted by themselves 
or certain other organisms present in the mouth, thus forming zoogloea 
masses which adhere to or become glued to the surfaces of the teeth. 

By this means the acid formed by the zymogenic organisms are kept in 
contact with the enamel and prevented from being washed away, as would 
undoubtedly be the case were it not for the presence of this protecting 
envelope, thus permitting the full chemical action of the acid upon the 
enamel to go on undisturbed. 

Caries of Dentin. — In studying the etiology of dental caries we have 
found that the same acid-producing ferments or micro-organisms were 
accountable for the production, initiation, and progress of the disease in 
all of the calcified tissues of the teeth, and that the saprogenic bacteria, 
or possibly the same zymogenic organisms, liquefied the basis substance 
and removed it, thus causing a gradual dissolution of these tissues until 
the entire organ is destroyed. 

The lactic-acid-producing organisms belong to the facultative variety of 



154 OPERATIVE DENTISTRY. 

bacteria. This lias been proved by the fact that they grow and develop 
equally well upon the surface of the enamel wherever lodgement can be 
found, iu the presence of the oxygen of the atmosphere, and in the tubuli 
of the dentin in which the oxygen of the atmosphere would be excluded 
by the presence of the fluids of the mouth. 

This fact explains the progress of caries which occasionally occurs 
under fillings having perfect margins, in which, for reasons that have 
seemed good to the operator, portions of decalcified dentin have been per- 
mitted to remain in the bottom of the cavity, but have not been thoroughly 
sterilized by dehydration and antiseptics. 

For the growth of micro-organisms three conditions are absolutely neces- 
sary, — heat, moisture, and a proper soil or food-supply ; cut off any one of 
these and the organism will cease to develop. 

The permanent arrest of caries, therefore, from the therapeutic stand- 
point, sums itself up into, first, so preparing a carious cavity that the food- 
supply of the micro-organisms and the decalcified tissue is thoroughly 
removed, and, secondly, in so inserting a plug or filling as to hermetically 
seal it. 

Without the ingress of moisture, or the presence of the elements from 
which the bacteria elaborate lactic acid, the progress of the disease must 
be arrested. 

Susceptibility and Immunity.— Susceptibility to caries has gener- 
ally been considered to be one of local environment, dependent upon the 
structural defects of the enamel and dentin and conditions which favored 
the development of the lactic-acid-producing micro-organisms. While 
immunity has been thought to be the result of perfectly developed dental 
tissues and conditions which retarded or prevented the formation of lactic 
acid, the degree of susceptibility, it was thought, was governed by the 
extent of the structural defects and the numbers and rapidity of develop- 
ment of the micro-organisms of decay. 

The investigations of Black (Dental Cosmos, May, 1895) and of Wil- 
liams (Dental Cosmos, March and April, 1897) have conclusively shown 
that dental caries is not dependent upon the structural defects or imperfec- 
tions of the dental tissues nor to their degree of calcification. 

Black determined by laborious and painstaking laboratory experimen- 
tation that human teeth show wide differences in physical structure of 
both the dentin and the enamel, ranging from that in which the enamel is 
practically perfect in all of its parts to those which present grave imper- 
fections of its physical structure, such as imperfectly closed developmental 
grooves, which leave fissures, pits, and openings of various sizes and 
shapes. 

The dentin also presents marked deviations from a physical perfection 
of structure. In some instances the dentin is very perfect, in others the 
interglobular spaces are exceedingly numerous and the granular areas 
present many physical imperfections. 

These investigators have both shown that these physical imperfections 
are in no wise a cause of dental caries, for among persons wholly immune 
to caries these imperfections are relatively as frequent as in those persons 



DENTAL CARIES. 155 

who suffer from caries, and that even when the imperfections of the 
enamel are such as to expose the dentin, no'decay has occurred in a life- 
time, as, for instance, in the imperfections of structure due to inherited 
syphilis and arrests of development caused by the exanthematous disease 
of early childhood, etc. 

Black * thinks these facts prove beyond a doubt that structural imper- 
fections, at most, only give greater opportunity for the active agents of 
caries to do their work, and have no further relation to that cause. In 
other words, physical imperfections of the enamel and dentin are simply 
local predisposing causes of the disease. 

Teeth, therefore, which present the most faulty structure may not 
decay, and will not decay in persons who are immune to caries, while 
teeth of the most perfect physical structure will succumb to caries in 
persons who are at the time susceptible to the disease. 

The active agents of caries are to be found in every mouth, and in 
sufficient quantities to produce the disease, and yet in certain individuals 
there is a complete immunity through a lifetime, while in others there 
may be various periods of susceptibility and immunity which seem to 
have no discovered relation to the local environment or condition of the 
health. 

The formation of the gelatinous plaques or zooglea masses by the caries 
fungus, as shown by Williams to be necessary to start the process of caries 
in the enamel, are not found in all mouths, though the organisms may be 
there and growing. The power of the organism to form gelatin, according 
to Black, seems to depend upon something in the saliva, the nature of which 
has not been discovered. These facts seem to throw some light upon the 
subject by indicating the direction in which future investigation should 
proceed. 

At the risk of being considered over-sanguine, the writer suggests that 
a means of preventing caries will yet be discovered, and that it will be in 
the nature of an antagonist to those organisms which have the power of 
forming gelatin in the oral fluids. 

Black is of the opinion that susceptibility is influenced by an inherited 
predisposition to the loss of the teeth, or of especial teeth at certain ages ; 
by changes of environment, either of climate or mode of life ; by the age 
of the individual, the young being most susceptible, while immunity 
usually comes with adult age ; and by the fluctuations of bodily conditions 
which change the character of the oral secretions. 

Phenomena of Caries of Dentin. — The invasion of the dental tis- 
sues by caries begins by the decalcification of the enamel, either in some 
fissure, pit, or crack, which may be only microscopic in size, or upon 
roughened surfaces which have given lodgement and protection to the 
zymogenic organisms, most commonly the approximal, labial, and buccal 
surfaces, as shown in Fig. 272. 

The margins of the cavity usually present more or less discoloration 
or opacity, while the enamel will be found softened by decalcification and 

* Dental Cosmos, September, 1899. 



156 OPERATIVE DENTISTRY. 

broken down. Sections of teeth cut through a cavity of decay in the 
enamel show immediately beneath an exposure of the dentin with soften- 
ing and discoloration. Closer inspection reveals, lying between the floor 
of the cavity and the pulp-chamber, several peculiarities in the color, the 
degree of decalcification, the transmission of light, and certain changes in 
the size and form of the tubuli. 

Pigmentation. — The color in ordinary caries at the surface of the 
cavity is yellowish brown, but it shades off as it reaches towards the pulp 
into the normal color of the dentin. In caries of rapid progress the color 
is white or yellowish white, while in caries of slow progress, or in arrested 
caries, the color is dark brown or black. The more rapid the progress of caries 
the lighter the pigmentation. It was thought at one time that the color was pro- 
duced by the carious process or by the micro-organisms. The fact, how- 
ever, that the discoloration can be easily and perfectly reproduced out of 
the mouth, with teeth which have been acted upon to any considerable 
extent by acids, proves conclusively that it is not due to the process of 
caries nor to bacteria. To accomplish this, place such teeth in water 
holding in solution a small quantity of sulphuretted hydrogen, fill the 
vessel, and place it in a dark closet to prevent decomposition of the solu- 
tion, and the tissues of the teeth, to a point as deep as that affected by 
the acid, will gradually assume a dark color. (Black.) 

Decalcification. — The degree of decalcification grows less and less 
from the surface of a carious cavity until normal dentin is reached. (See 
Fig. 273.) 

The outermost layers of the dentin will generally be found completely 
decalcified, the basis substance being soft and leathery, and having an 
odor like that of gangrenous lung-tissue. 

Beyond the line of partial decalcification is a transparent zone known 
as the zone of Tomes (Fig. 274), which its discoverer and Magitot have 
maintained was caused by vital action, or resistance of the tissue to the 
encroachment of the disease, and produced by the filling up of the den- 
tinal tubuli with calcific material, and thus making it more easily pene- 
trated by rays of light. It is in appearance very similar, both macroscopi- 
cally and microscopically, to the senile dentin, the dentin of the crowns 
of teeth worn down by mechanical abrasion, and the roots of teeth which 
have remained long in the mouth without dental decay. 

Miller, by quantitative analysis, has shown that it contains more 
calcium salts than the surrounding normal dentin. Walkhoff thinks that 
it is an evidence of vital or formative activity induced by the stimulation 
of irritation, causing the production of an intercellular substance at the 
surface of the cells and primarily of their offshoots. 

It will be noticed, also, as pointed out by Gysi, that the transparent 
zone which lies between the carious dentin and the pulp is continuous 
with a new formation of dentin— secondary dentin — upon the Avail of the 
pulp-chamber (Fig. 275). 

Burchard thinks " these evidences point to the truth of Walkhoff 's 
explanation of the process, and indicate that the transparent appearance 
is the result of vital reaction." 






Fig. 272. — Vertical section of deciduous molar, showing caries of enamel which started in a fissure, and 
of the dentin which had its origin in an approximal cavity of decay. X 8. 




■Vrt L„ 

3.— Carious dentin from base of cavity. (V. A. Latham.) X 46.66. A, infected tubules; B, en- 
larged tubules ; C, infected interglobular spaces. 




Fig. 274. — Undermining caries of enamel, showing transparent zone of Tomes at A. (R. R. Andrews.) 







Fig. 276.— Dentinal tubules from infected dentin, showing enlargement of the tubules and the 
presence of micro-organisms within them. (Tomes.) 



DENTAL CARIES. 



157 



It is still, however, an open question as to whether the transparent 
zone is or is not a real zone of resistance to the encroachment of the dis- 
ease and effective in retarding its progress. 



Clinical observation and ex- 



Fio. 275. 




Longitudinal ground-section of crown of an inferior molar of a negro. This figure is drawn from a 
ground and polished section mounted in Canada balsam. (Gysi.) E, enamel ; D, dentin ; C, cement ; p, 
pulp-chamber; a, large decay, from the grinding surface; b, small decay, from the mesial surface ; cs, 
7one of septic invasion and discoloration ; e, partially decalcified and discolored enamel around the 
carious cavity ; 2, dark zones ; s', clearer zones ; z'p, oldest zones, where putrefaction of the tooth- 
cartilage begins ; c, outer transparent zone, or zone of Tomes ; sd, secondary dentin, caused by irritation ; 
s'd', secondary dentin deposited by normal physiological process, recession of the pulp. 



perience would seem to indicate that it has an effect upon the dentin 
which renders it more resistant to the progress of the disease. 

Expansion of the Tubuli, — Sections of carious dentin cut parallel 
with the long axis of the tubuli, which have been stained with fuchsin or 



158 



OPERATIVE DENTISTRY 



gentian violet, show these tubules to be considerably enlarged, with swell- 
ings or molecular expansions upon individual tubes (Fig. 276). 



Fig. 277. 



Fig. 278. 



Fig. 279. 



I 

i 



8& 



Single tubule filled with cocci 
(Miller.) 1100:1. 



Single tubule filled with rods. 
(Miller.) 1100:1. 



Single tubule showing a mixed 
infection with a pleomorphous 
bacterium. (Miller.) 1100:1. 




1 



Longitudinal section of decayed dentin, showing infection with 

Decayed dentin, showing rod- and thread-forms. (Miller.) a, tubule distended, but walls 

a mixed infection with cocci still comparatively intact ; 6, d, tubular walls broken through and 

and bacilli. (Miller.) 400:1. the dentin in a state of complete dissolution ; c, tubules out of focus. 

Circa 500 : 1. 

There is, however, no uniformity in the enlargement of the tubules or 
of the nodular expansions. Some tubules will be very much enlarged, 




Fig. 282.— Vertical section of infected human dentin, showing the presence of micro-organisms 
enlargement of the tubules. (R. R. Andrews.) 






.« * # 



*/>v%>t>* ' ' 



EM* * - - ■•■• * .."^jr,- .~ — >J #■ _ ^ 










/ *^ij-*: 



Fig. 283.— Transverse section of infected human dentin, showing the presence of micro-organisms and 
various enlargements of the tubules. (R. R. Andrews.) 



r^ 




r 



m 



*-. i 







i 

if 






y 



Fig. 284.— Vertical 



scted human dentin, showing tubules greatly enlarged and filled with 
micro-organisms. (R. R. Andrews.) 




-Infected human dentin, showing confluence of enlarged tubules forming cavities which are 
filled with micro-organisms. (R. R. Andrews.) 




Fig. 2.%.— Oblique seetioi 



(1 human dentin, showing confluence of tubules forming larger 
cavities. (R. R. Andrews.) 




Fig. 287.— Infected human dentin, showing advanced state of infection. (V. A. Latham. ) ■, 100. 
A, A, A, micro-organisms in the tubuli. The dark portion shows decalcified and discolored areas of 
dentin. 




Fig. 288.— Transverse section of human dentin, showing pipe-stem appearance of infected dentinal 
tubules. (Tomes. ) 




Fig. 289.— Transverse section of dentinal tubules. (V. A. Latham.) X 162.5. The dark tubules show- 
infection with micro-organisms and the pipe-stem appearance described by Tomes. 



DENTAL CARIES. 159 

while others will seem to be only slightly affected. Walkhoff declares the 
dentinal tubuli are regularly enlarged, and that the varicosities appearing 
at irregular intervals are occasioned by the drying of the specimen. 

Upon further examination with higher powers of the microscope it will 
be discovered that the tubuli in the superficial, softened, and decalcified 
dentin are filled with bacterial forms, cocci, rods, and threads, the coccus 
forms predominating. 

Fig. 277 shows a single tubule filled with cocci; Fig. 278, one filled with 
rods. Fig. 279 shows a mixed infection of cocci, diplococci, short and 
long rods, or infection with a pleomorphous bacterium (polymorphous) . 
Fig. 280 shows several tubules in decaying dentin filled with a mixed in- 
fection of cocci and bacilli, while Fig. 281 shows a longitudinal section of 
decayed dentin which is infected with rod- and thread-forms. Figs. 282, 
283, 284, 285, 286, and 287 show the micro-organisms as they appear in 
slides made from decaying dentin. 

In the deeper layers of decalcified dentin the bacteria become less and 
less in numbers, until they finally disappear. Beyond this non- infected 
point, however, there is a zone of partially decalcified dentin, the removal 
of the lime-salts being caused by the solvent action of the lactic acid pro- 
duced by the bacteria lodged within the tubules. 

Cross-sections of decaying dentin exhibit a very peculiar appearance 
of the dentinal tubuli, or rather of the sheaths of Neumann (Fig. 288), 
which are, according to Tomes, greatly thickened, and the lumen partially 
obliterated, giving the section the appearance of having been built up of a 
multitude of tobacco-pipe-stems (Fig. 289). Such is the condition at a 
certain stage of their disorganization. 

In longitudinal sections examined at a later period the sheaths appear 
to break up into short lengths or sections, and are found twisted ; and, 
finally, the whole tissue undergoes disorganization into minute granules,, 
which are by degrees washed away by the fluids of the mouth. 

Disorganization of the Dentinal Fibres.— The contents of the 
tubuli — Tomes fibres — also appear to undergo disorganization and break 
up into pipe-stem sections or short rods (Fig. 290). This was first noticed 
by Tomes. 

This peculiar aj)pearance has not been satisfactorily explained. Tomes 
says, "These rods may be portions of consolidated fibrils, or they may be 
bits of the sheaths of Neumann, or they may be mere casts of the enlarged 
tubules." 

Wedl, however, thinks the statement that they are consolidated fibrils 
is not proved. Miller is of the opinion that they are calcified fibrils, as 
he has observed their rapid disappearance while viewing them under the 
microscope when the specimen was treated with dilute sulphuric acid. 

Another peculiarity is also observed iu the dentinal tubuli in the form 
of shining or glistening granules. These are seen occurring in the early 
stage of caries, and sometimes in the zone just in advance of the carious 
process. Some observers, Tomes, Magitot, and others, have thought them 
to be lime formations thrown out by the odontoblasts for the purpose of 
resisting the advance of the disease. Wedl, Black, and others looked 



160 OPERATIVE DENTISTRY. 

upon them as fat-globules. Baurne has shown conclusively, however, that 
these globules are not particles of fat, since they do not disappear when 
treated with sulphuric ether. 

Miller thinks these granular bodies cannot be lime formations thrown 
out by the pulp, for they are found in cariesof pulpless as well as living 
teeth, but regards it as not improbable that they have the same origin as 
the rod-shaped (pipe-stem) formations found in the tubuli. 

PENETRATION OF CARIES. 

Generally speaking, the line of progress or penetration of caries may be 
stated to be in the direction of the tubuli, or, in other words, from the 
surface towards the pulp. This, however, is not universally the case, for 
occasionally cavities will be found which have been formed in a direction 
transverse to the tubuli. The conditions which favor the formation of 
such cavities are usually, if not always, due to faulty formation of the den- 
tin, interglobular spaces, thick granular layer, or other imperfections in the 
deposition of the calcoglobulin and its calcification. Such spaces offer 
admirable facilities for the penetration and growth of the micro-organisms 
and the lateral extension of the disease. Fig. 291 shows interglobular 
spaces filled with micro-organisms. In the ordinary form of caries the 
disease travels along the tubules by the penetration of the fungi into these 
open spaces (Figs. 292 and 293), and exposure of the pulp takes place 
before lateral spreading has progressed to any great extent. This is espe- 
cially true of teeth of the best development, for observation proves that 
exposure of the pulp will occur in this class of teeth with the least destruc- 
tion of tissue. "The more perfect the development the more completely 
will the penetration be confined to the direction of the tubules." (Black.) 

CARIES OF CEMENTUM. 

The etiology of caries of ceinentuin is so nearly like that of decay of 
dentin that it hardly needs a special description, except that which grows 
out of the difference in the histologic structure. Decalcification is caused 
by the same micro-organisms that produce caries of dentin. The fungi first 
attack the calcified rods known as Sharpey's fibres, and penetrate to the 
cement- corpuscles and their canaliculi, decalcifying the surrounding tissue 
as in decay of dentin. The organic substance is then liquefied by the 
saprophytic bacteria and washed away. 




290.— Longitudinal section of infected human dentin, showing the pipe-stem appearance of the 
tubules described by Tomes. (R. R. Andrews.) 




Fig. 291.— Infected human dentin. (V.A.Latham.) X 162.5. A, micro-organisms in the tubuli ; 
B, B, micro-organisms in the interglobular spaces. 






Fig. 292.— Infected human dentin. (R. R. Andrews.) A, A, A, showing penetration of micro-organisms 

in the tubuli. 




Fig. 293.— Infected human dentin. (R. R. Andrews.) A, 

in the tubuli. 



nving penetration of micro-organisms 



CHAPTEE IX. 

DENTAL CARIES (CONTINUED). 

Varieties of Caries. — The older writers were in the habit of dividing- 
caries into several varieties, according to the physical signs presented by 
the disease, believing that these signs represented distinct forms of the 
affection, which they classified as follows : caries humida, moist caries ; 
caries acuta, acute or rapid caries ; caries chronica, chronic or slow caries ; 
and caries sicca, dry caries or arrested caries. This classification of the 
disease is no longer used, as the affection is now known to be one and the 
same from beginning to end, the differences in the physical signs being 
due to the differences in the character or perfection of the structure of the 
teeth, the conditions of the general health, the character of the oral secre- 
tions, and the hygienic conditions which prevail in the mouth. All of 
these factors have an influence upon the extent and the rapidity in the 
progress of the disease, and are responsible for the differences in the 
physical signs. 

Stages of Caries. — It is customary with most writers in describing 
dental caries to divide the disease into various natural periods or stages. 
Magi tot divided the affection into three periods,— -first, second, and third. 

The first period he confined to the dissolution of the enamel. The 
second period to the destruction of the dentin. The third period to the in- 
volvement of the pulp-chamber. 

A more exact division of the stages of the disease recognizes four dis- 
tinct periods or degrees of progression : 

First, superficial or incipient. 

Second, progressive. 

Tliird, deep-seated. 

Fourth, complicated. 

In the first, or superficial or incipient, stage (Fig. 294, A) the disease in- 
volves only the enamel or the cementum. This may be confined to the 
surface of these tissues or involve their whole thickness, forming a per- 
ceptible cavity, which may be more or less sensitive to sweets, acids, or 
thermal changes. 

In the second, or progressive, stage (Fig. 294, B) the enamel or the cemen- 
tum has been penetrated and the disease is extending into the dentin, 
forming a deeper cavity. 

The third, or deep-seated, stage (Fig. 294, 0) represents a more serious 
involvement of the dentin, reaching almost to the pulp-chamber ; not, how- 
ever, exposing the pulp, but causing irritation and making it necessary to 
protect it by some form of capping before inserting a filling. 

In the fourth, or complicated, stage (Fig. 294, D) the disease has extended 
to the pulp-chamber, causing inflammation or death of the pulp. 

The rapidity with which caries sometimes progresses often makes it 

11 161 



162 



OPERATIVE DENTISTRY 



Fig. 294. 




Vertical section of a lower 
molar tooth showing stages of 
caries. 



impossible to distinguish the various stages one from another, while in 
such cases especially there is a lack of pigmentation. This form of the 
disease, which is sometimes termed white decay (caries humida), not infre- 
quently in the course of a few weeks destroys one-half or more of the 
tooth and exposes the pulp. In the ordinary form of caries (caries acuta), 
sometimes designated as brown decay, the time required for the disease to 
penetrate from the enamel to the pulp- chamber 
is from six to eighteen months, while in that 
form known as black decay (caries chronica) the 
process is so slow that several years are required 
for the disease to penetrate to the pulp. 

Symptoms. — The symptoms of caries in its 
earlier stages vary from a mild drawing or gnaw- 
ing sensation to that of acute pain. These symp- 
toms are induced by the exposure of the dentinal 
fibrils to the irritating effects of sweets, acids, 
salt, changes of the temperature, and instrumen- 
tation. 

Tbe character and severity of the symptoms 
vary with different individuals, and in the same 
individual at different times and under varying 
circumstances. 

Temperament has much to do with the char- 
acter and severity of the pain experienced by people suffering from dental 
caries. Individuals possessed of exalted nervous irritability surfer much 
more than others, while in the same individuals certain conditions of 
health, like anaemia, dyspepsia, nervous prostration, mental worry, or 
other causes which depress the vital forces, as chlorosis and pregnancy, 
often greatly increase the susceptibility to pain and render the symptoms 
of caries very acute. 

It is also a notable fact that many times in the first and second stages of 
the disease there will be great sensitiveness of the dental tissues, but as 
the process advances the sensitiveness diminishes until the pulp becomes 
involved. 

Under ordinary circumstances the superficial layers of carious dentin 
are much more sensitive than those which lie deeper. This is also true of 
normal dentin. The peripheral extremities of the dentinal fibrillar, or that 
portion of them which lies directly beneath the enamel and cementum, 
assuming that the fibrillar carry sensation, are much more sensitive than 
at their deeper parts. This is true of peripheral nerves everywhere. The 
irritation attendant upon the carious process greatly increases the sensi- 
tiveness of the fibril Ire, and produces what is termed hypersensitive dentin. 
In certain individuals, however, the sensitiveness of their teeth is so slight 
that carious cavities can be excavated with little or no pain so long as the 
pulp is not invaded, the character or rapidity of the carious process seem- 
ingly making no difference. 

And yet some of these individuals would be classed as possessing the 
temperament known as nervous, while others would be classed as 



DENTAL CARIES. 163 

bilious, and lymphatic. Does this lack of irritability to stimuli, applied to 
the dentinal fibrillar, lie in the fibrillar themselves or in the general ner- 
vous system of the individual ? Or is there some difference in the char- 
acter of the micro-organisms which produce the disease, or in the irritating 
quality of the acid produced by them 1 

These are the questions which the writer has often propounded to him- 
self, but has never been able to satisfactorily answer. 

In the third, or deep-seated, stage of caries, severe pain is often experi- 
enced from the entrance of irritating substances or their application to the 
diseased dentin. When decalcification of the dentin has progressed to a 
point that reaches the pulp, but not exposing it, irritating substances 
having gained access to the cavity of decay, often cause hyperemia of the 
pulp, and produce paroxysms of pain of a more or less severe character, 
lasting for a few minutes, or it may be for a much longer period. The irri- 
tation of the pulp may be so severe as to produce inflammation and death 
of the organ. 

The fourth, or complicated, stage is usually ushered in by pain of a severe 
and prolonged character, from the invasion of the pulp-chamber, which,- 
permitting septic infection, causes inflammation and death of the pulp. 

It often happens, however, that the vitality of the pulp has been de- 
stroyed by the irritating and septic conditions accompanying the deep- 
seated stage of the disease, and the pulp -chamber will be found to be oc- 
cupied by the remains of a gangrenous pulp ; or the exposure of the pulp 
may have resulted in a low grade of suppurative inflammation which has 
become chronic; or inflammation of a chronic type may have resulted in 
hypertrophy of the pulp, which has more or less completely filled the 
cavity of decay. 

Sensitiveness and pain, however, do not always accompany the progress 
of caries, even in the latter stages of the disease, and it is not uncommon 
with certain individuals to find the pulp-chamber invaded and the pulp in 
a gangrenous condition without pain being experienced at any period of 
the carious process. 

Diagnosis. — The diagnosis of caries can usually be made without 
much trouble, and yet in some cases it becomes a matter of considerable 
difficulty. The disease is to be sought for in those locations which expe- 
rience has taught the operator are the most vulnerable, and therefore the 
most likely to furnish evidences of tissue disintegration. These locations 
have already been indicated as found in the enamel in the natural fissures, 
sulci, and pits, upon the approximal, buccal, and labial surfaces, and not 
infrequently in cracks caused by traumatic injuries, and the expansion and 
contraction of the tissue incident to the great and rapid changes in tem- 
perature to which they are often subjected in going from a warm room to 
a cold outside atmosphere, often many degrees below zero ; or in immedi- 
ately following a mouthful of some hot fluid with another one of ice- 
water, a custom very common among Americans. These imperfections in 
the initial stage of the disease are frequently microscopic in size, but 
are, nevertheless, sufficiently large to give access to the organisms of 
caries. 



164 OPERATIVE DENTISTRY. 

The approximal surfaces of the teeth are the locations which are most 
often the seat of caries, from the fact that the inter-approxiinal spaces give 
constant lodgement for alimentary debris, and fluids are held by capillary 
attraction, thus favoring the processes of fermentation. 

The lingual, labial, and buccal surfaces are most free from the carious 
process, and in the order named, while their most vulnerable points are 
the developmental furrows and pits and the cervical margins at the free 
edge of the gums. 

Parreidt has ascertained that on an average one hundred carious teeth 
would be composed of twenty-six incisors and cuspids, twenty-eight bicus- 
pids, and forty-six molars. Of the incisors and cuspids, ninety-eight per 
cent, on an average, decay on the approximal surfaces, and only four per 
cent, on the incisive, lingual, and labial surfaces. The bicuspids decay 
most frequently upon the approximal surfaces, the percentage being ninety- 
two ; while the molars decay most often upon the morsal surfaces, the per- 
centage being seventy-two ; the approximal surfaces, twenty-eight ; the 
labial and lingual, two. He says, further, "According to my observation, 
the first appearances of caries occur in sixty-four cases out of one hundred 
on the approximal surfaces of the teeth." These surfaces are often so 
close together that it is with extreme difficulty that the eye can detect the 
disease in its incipient stage without resorting to mechanical appliances 
for separation or the use of reflected artificial light. 

The most difficult cases to diagnosticate, however, are those which give 
no evidence to the eye of disintegration of the enamel, but are so far pro- 
gressed as to cause acute and severe pain. These most often begin in some 
tiny pit or fissure upon the morsal surface of the molars and bicuspids, or 
the buccal surfaces of the molars, in which the process of decay has been 
so rapid and the point of entrance of the micro-organisms so small that 
there has been no change in the color of the affected tissue. The discovery 
of such cases calls for a high degree of skill and unlimited patience. 

Many such cases have been entirely overlooked by practitioners of con- 
summate skill and large experience, and diagnosticated as neuralgia or as 
imaginary pains. 

Too much care cannot be exercised in the examination and diagnosis 
of these cases, as a failure to find the cause often entails great suffering 
upon the patient and loss of reputation to the consultant. 

The means which are used in examinations of the mouth have been 
fully described in Chapter VI. , to which the reader is referred. 

Prognosis. — The prognosis of dental caries, if no therapeutical or sur- 
gical means are introduced for its arrest or control, is, as a rule, extremely 
bad, for nearly every tooth so attacked will be sooner or later entirely 
destroyed. 

The prognosis for those teeth which are operated upon according to the 
most approved methods of conservation will depend in large measure upon 
the thoroughness with which these methods have been applied, and the 
care which is afterwards given by the patient to the hygienic conditions of 
the mouth. 

Eecurrence of the disease at the margins of the filling after a few years 



DENTAL CARIES. 165 

will invariably occur if the operation has been faulty, or the patient has 
been neglectful of the ordinary means of cleansing the teeth and preserving 
the mouth in a healthful condition. 

The disease in individual teeth may be arrested at any stage of its 
progress, and recurrence prevented, provided the therapeutic measures 
above indicated are faithfully followed, but the tendency to the affection 
cannot be eradicated except by the removal in toto of the predisposing and 
exciting causes. 

Much, however, may be accomplished by the institution of certain pro- 
phylactic measures, which will be discussed in the following chapter. 



CHAPTER X. 

TREATMENT OF CARIES. PROPHYLAXIS. 

Definition. — Prophylaxis (from the Greek -npocpukasis, caution; itpo, be 
forehand ; <poXaa<ru)^ to guard, to prevent). The prevention of disease ; 
preventive measures ; preventive medicines ; hygiene. 

The treatment of dental caries resolves itself into the application of 
those measures which aim at the prevention of the disease.— prophylaxis, — 
and those which are instituted to arrest the progress of the affection and 
remedy the defects and injuries which have been caused by it, — thera- 
peutics. 

Prophylactic treatment comprehends all of those measures which are insti- 
tuted for the purpose of removing the exciting causes of the disease, and, 
as far as possible, rendering inoperative those causes which are predis- 
posing factors. 

The removal of the exciting causes of dental caries should, from the 
importance of the subject, receive our first and most earnest attention. As 
already indicated in a previous chapter, the science of dental surgery has 
not yet come up to the demands upon it in the prophylactic treatment of 
dental caries, and until such time as it does, the profession will not be 
fulfilling its highest obligations to its clientele. 

Cleanliness of the mouth and teeth is the greatest of all prophylactic measures 
which can be instituted against dental caries. This statement needs no verifi- 
cation, for it should be patent to every one whose observation and opera- 
tive experience have extended over even a limited period of time, as they 
must have noticed how exceedingly rare it is for caries to occur upon 
smooth surfaces of the teeth which are fully exposed to the friction of foods 
in mastication and the cleansing action of the tongue, lips, or cheeks, and 
the oral secretions. 

The prevention of caries, therefore, should aim at securing perfect 
cleanliness of the mouth, for this implies the destruction of the zymogenic 
micro-organisms of decay, and the removal of their acid products and all 
fermentable material, as well as the correction, so far as possible, of those 
constitutional conditions which lower the vitality and tend to vitiate the 
oral secretions. 

The value of perfect oral cleanliness is not generally understood by 
the public. Most people brush their teeth for purely cosmetic reasons, 
and not to prevent disease. It therefore becomes the duty of every dentist 
to so instruct his clients in the need of oral hygiene as a preventive measure 
against disease, and the means by which they may secure this condition, 
that they will fully appreciate its value, and intelligently strive to carry 
out the instruction in all of its details. These measures should con- 
sist of : 
166 



TREATMENT OF CARIES. 167 

1. Instruction to parents in the care of their children in relation to 
general measures of hygiene, — food, clothing, exercise, pure air, bathing, 
etc., — that the best possible development of the whole body, and conse- 
quently of the dental organs, may be secured. 

2. In such a regular and systematic mechanical cleansing of the teeth 
and the mouth that the acid-producing bacteria and the fermentable sub- 
stances upon which they grow may be thoroughly removed or reduced to 
the minimum. 

3. By prohibiting or so limiting the consumption of such foods and 
confections as furnish the material for acid formation that the chief source 
of lactic acid may be eliminated or greatly reduced. 

4. In such a systematic and intelligent use of antiseptics that the 
zymogenic bacteria may be destroyed, or their number and action so 
limited as to render them practically harmless. 

Miller, in his exj)eriinents with the zymogenic bacteria of the mouth 
and the influence of certain prophylactic measures upon them, has ren- 
dered a service to humanity which is beyond calculation. 

The great value of mechanically cleansing the mouth with the brush, 
toothpick, floss-silk, etc., he demonstrated by taking ten cubic centi- 
metres of saliva from the mouth before cleansing it, and adding half a 
gramme of starch, and placing the mixture in the incubator. After 
cleansing the mouth an equal amount of saliva and starch were mixed, 
and, as before, placed in the incubator. The first mixture not only 
showed earlier signs of fermentation than the second, but also formed more 
acid in a given time. In later experiments he determined the amount of 
acid produced in two equal infections from the same individuals before 
and after a careful cleansing of the mouth and teeth, and found the amount 
of acid produced by the latter sometimes as low as one-fourth that of 
the former, while after the use of strong antiseptic mouth-washes the 
amount was reduced to nil. u There is no known solution, alkaline or 
antiseptic, applicable in the human mouth, which will penetrate between 
the teeth, or to the bottom of fissures and cavities, — when these are filled 
with food, — in sufficient quantity to have any appreciable effect. Therefore 
before all antiseptics or alkaline washes come the tooth-brush, toothpick, 
and floss-silk." 

Thorough mechanical cleansing of the teeth can only be accomplished 
by the use of all these means. The brush alone, even when used with the 
greatest intelligence, will not thoroughly remove the food dSbris from the 
inter-approximal spaces, and it becomes necessary to follow its use with 
the toothpick, and afterwards with waxed floss-silk drawn between the 
teeth, in order to free the proximate surfaces of all fermentable substances. 
To insure a perfect hygienic condition of the mouth this cleansing process 
should be repeated after every meal, and the mouth sterilized with an 
antiseptic solution after each cleansing, on retiring at night and upon 
rising in the morning. 

The importance of this statement cannot be over-estimated nor too 
strongly impressed upon those seeking the services of the deatal specialist,- 
for therein lies the salvation of the teeth. Too many people imagine that 



168 OPERATIVE DENTISTRY. 

antiseptic mouth- washes are sufficient to correct the tendency to fermenta- 
tion, regardless of the fact that when food dSbris is retained between the 
teeth and in the sulci and fissures the antiseptics do not penetrate these 
substances, and therefore the action of the zymogenic bacteria is only re- 
tarded upon the surfaces, while in the deeper portions it still goes on with 
unhindered rapidity. 

Dentifrices of various composition are used as adj uncts to the mechani- 
cal action of the tooth-brush ; these are made in the form of powders, 
pastes, and soaps. 

Miller places no particular value on tooth-powder as a means of 
cleansing the teeth. He admits that the external surfaces, particularly of 
the front teeth, may be kept whiter by the use of tooth-powder, but thinks 
the centres of decay are more liable to become stopped up than to be 
cleansed by tooth-powder, particularly when they contain insoluble sub- 
stances. 

He would recommend tooth-soaps, in so far as they dissolve fatty sub- 
stances without attacking the teeth, and, furthermore, possibly make the 
penetration of the bristles of the tooth-brush into the centre of decay some- 
what more easy. He thinks the dentifrice should be made of neutral soap 
and have a neutral or slightly alkaline reaction, and finally says, u Under 
all conditions, however, the chief thing is the thorough mechanical 
cleansing of the teeth." 

Tomes says, "In many respects tooth-soaps are to be preferred to 
powders." 

The writer, however, has never been able to appreciate the advantages 
of the tooth-soax3S over tooth-powders or tooth-pastes, for there are few 
mouths in which the teeth can be kept bright and clean without the 
polishing effect of some form of tooth-powder containing calcium carbonate 
or magnesium carbonate. 

All good tooth-powders and pastes should contain a sufficient amount 
of the best castile soap to gain the advantage of its dissolving action upon 
fatty substances. The following formulae will be found useful. 

Tooth-powder. Tooth-paste. 

R Precipitated chalk 3" viii ; R Precipitated chalk % viii ; 

Pulv. orris root 3" iv ; Pul v. orris root 3" i v ; . 

Pulv. cinchona bark 5 iv ; Pulv. cinchona bark 3* i v ; 

Pulv. cinnamon 5 v ; Pulv. castile soap 3 ii ; 

Pulv. castile soap 3 ii ; Bicarbonate of soda 3 i ; 

Pulv. white sugar 3" iv ; Oil of gaultheria f £ss ; 

Oil of lemon gtt. xx ; Glycerol, q. s. to make a thick paste. 

Oil of rose gtt. ii. Mix, pulverize, and sift the dry ingredients 

Mix, pulverize, and sift through a fine before adding the oil of gaultheria 

hair sieve. and the glycerol. 

It is not necessary to give more than one or two formula? for dentifrices, 
as a large variety of good powders, pastes, and soaps have been placed 
upon the market by the dental dealers, most of which are entirely reli- 
able, and the dentist may j)lace them in the hands of his clients with con- 
fidence that they are what they are represented to be. 



TREATMENT OF CARIES. 



169 



Miller, in his experiments with regard to the effects of various anti- 
septics upon the zymogenic function of the niouth-bacteria, found great 
difficulty in selecting substances to which serious objections could not be 
raised, either from their injurious effects upon the teeth or the mucous mem- 
brane, their general toxic effects, or from their disagreeable taste or smell. 

The following substances, in solutions admissible for use in the mouth, 
were tested by him as to the time necessary to devitalize bacteria. Several 
of them were found to accomplish this result inside of one minute. 



Antiseptic. 



Salicylic acid* 

Benzoic acid* 

Listerine 

Salicylic acid 

Bichloride of mercury 

Benzoic acid 

Borobenzoic acid 

Thymol 

Bichloride of mercury 

Peroxide of hydrogen . . ." 

Carbolic acid 

Oil of peppermint in agreeable strength. 

Permanganate of potash 

Boric acid 

Oil of wintergreen 

Tincture of cinchona 

Lime-water 



< 'oncelitiat ii hi. 



1 to 
1 to 



100 
100 



1 to 200 
1 to 2500 
1 to 200 
lto 175 
1 to 1500 
1 to 5000 
10 per cent, 
lto 100 



1 to 4000 
1 to 50 



1 to 18 



I minute. 

% minute. 

| to i minute. 

h minute. 

J to f minute. 

1 to 2 minutes. 

1 to 2 minutes. 

2 to 4 minutes. 
2 to 5 minutes. 
10 to 15 minutes. 
10 to 15 minutes. 
5 to 10 minutes. 
More than ] 5 minutes. 
More than 15 minutes. 
More than 15 minutes. 
More than 15 minutes. 
No action. 



It will appear that only a very few of these substances are really ser- 
viceable for the purpose of disinfecting the mouth, for the reason that the 
time necessary to destroy the vitality of the bacteria is too long. Solutions 
which will not sterilize the oral cavity in from one to two minutes would 
possess little value as antiseptic mouth-washes, for usually such solutions 
do not remain in the mouth for more than a few seconds, or at most for a 
minute. 

According to Miller, " The bichloride of mercury is the most active, 
not only because it has the highest antiseptic power, but because its action 
continues for a longer time." 

Lister, who used it very extensively in his surgical practice at one 
time, has gone back to carbolic acid, for the reason that a five to ten per 
cent, solution penetrates the tissues to a greater depth than a 1 to 500 
solution of bichloride of mercury. Strong bichloride solutions coagulate 
the albumin upon the surface, and thus form a barrier against the pene- 
trating effect of the drug. 

Listerine was found by Miller to be a very efficacious preparation for 
sterilizing the mouth. It produced devitalization of mouth- bacteria in 
from one-fourth to one-half a minute. It should be applied to the tooth- 
brush or diluted one-half as a mouth-wash. 



* Salicylic and benzoic acids may be applied in this concentration only on the 
brush. 



170 OPERATIVE DENTISTRY. 

Pasteurine, borolyptol, thyruozone, and other similar preparations which 
are combinations of benzoic acid, thymol, formalin, etc., are efficacious in 
sterilizing the mouth, have a favorable tonic action upon the soft tissues, 
and reduce inflammation. 

Miller found that the oil of wintergreen and other similar aromatic 
substances, which usually form an important constituent of mouth-washes, 
have, in an adaptable concentration for use in the mouth, very little anti 
septic action. He, however, excepts oil of peppermint from this category 

Black extols the antiseptic qualities of oil of cassia, oil of cinnamon 
and oil of cloves, and thinks they have a much higher antiseptic power 
than oil of peppermint. 

Koch, on the other hand, found oil of peppermint to have an anti- 
septic action nearly seven times as strong as oil of cloves. Miller thinks 
this difference between these astute observers may be accounted for in the 
difference of the bacteria experimented upon. 

Thiersch's antiseptic solution the writer has found to be a most valuable 
sterilizing mouth-wash. It is slightly bitter to the taste, but this may be 
disguised by the addition of a few drops of oil of cassia, oil of pepper- 
mint, or oil of wintergreen. 

The formula is as follows : Salicylic acid, four parts ; boric acid, twelve 
parts ; water, one thousand parts. Flavor to suit the taste. It may be 
used ad libitum. 

The most effective method of using antiseptic mouth-lotions is that 
suggested by Ottolengui, to force the solution between the teeth and over 
the surfaces by means of an atomizer. 



CHAPTER XL 

TREATMENT OF CARIES (CONTINUED). MEDICATION. EXCISION. 

Definition. — Therapeutics (from the Greek depaxeuTix-r}, curative). 
That branch of medical science which considers the application of reme- 
dies as a means of cure. 

The therapeutic treatment of dental caries consists in the application 
of certain surgical principles and mechanical procedures which are adapted 
to the peculiar nature and causation of the disease, the character of the 
tissue affected, the extent and the rapidity of the progress of the affection, 
its complications, the environment, and the liability of the disease to re- 
currence. 

The surgical procedures which are applicable to the cure of dental 
caries are Medication, Excision, and Obturation or Filling. 

MEDICATION. 

Treatment by medication consists of impregnating the softened sur- 
face of enamel or dentin with nitrate of silver or some other salt which 
will destroy the bacteria which have penetrated these tissues, and so change 
the character of the impregnated tissues that they no longer offer a favor- 
able field for the growth and development of the lactic-acid-producing 
fungi. 

The idea of arresting dental caries by the application of the nitrate of 
silver was presented more than fifty years ago. It, however, never came 
into general use except in the treatment of superficial caries in the pos- 
terior part of the mouth. The great objection which has been raised 
against its employment is the fact that it stains the eroded enamel and 
the exposed dentin jet-black, thus giving a very unsightly appearance to a 
tooth so treated. If the treatment, however, has been successful, the black 
stain gradually disappears, leaving a polished mahogany-brown surface, 
which is immune to caries. 

Stebbins (1891) revived interest in this method of treatment by advo- 
cating its use for the arrest of caries in the temporary teeth. The black- 
ening of the decayed surface in these cases is not so objectionable as in the 
permanent teeth, while it often renders the preservation of the deciduous 
teeth a much easier task than by the more difficult, laborious, and painful 
operation of inserting a filling. 

Stebbins advocated the application of a solution of silver nitrate to the 
carious cavity by means of a small pointed stick inserted in a socket in- 
strument or porte-carrier made for the purpose. 

He found that many cases needed no further treatment, as the carious 
process was completely arrested, while in others, after a few months, a 

171 



172 OPERATIVE DENTISTRY. 

second application was necessary. In many cases he thought it advisable 
to fill the cavities with gutta-percha after the application of the silver 
nitrate. 

Peirce recommends that application be made by means of pieces of 
blotting-paper of suitable size, saturated in a forty per cent, solution of 
the drug, and kept ready for use. 

Kirk objects to the use of blotting-paper or cotton as a means of apply- 
ing the solution, for the reason that "the contact of silver nitrate with 
vegetable fibre of any sort involves not only a destruction of the fibre, but 
also of the silver nitrate, so that the preparation in a short time loses its 
desirable qualities." He advises instead the use of asbestos felt which 
has been heated before the blow-pipe to eliminate all vegetable matter 
previous to saturation with the solution. 

Holmes suggests, in the treatment of proximal cavities, that the walls be 
"cut away to a Y shape, and with a piece of gutta-percha softened by 
heat, of the proper size of the space, bring the surface to come in contact 
with the diseased part of the teeth in contact with the powdered crystals 
of silver nitrate, and carry it into place in the tooth or teeth prepared for 
its reception, packing it firmly, and leaving it there to be worn away by 
use in mastication. When that takes place the surface of the teeth will 
be found black and hard, with no sensitiveness to the touch or to changes 
in temperature, and they will remain so indefinitely. In case the child 
is so timid as to prevent this course, dry the cavity, take out as much 
softened dentin as the patient will permit, carry the crystals on softened 
gutta-percha into the cavity, and pack it there, leaving it until such time 
as desirable to make a more thorough operation." 

Goddard deprecates the practice of making Y-shaped separations in 
these cases, and believes it better to open proximal cavities from the 
morsal surface, "as the full diameter of the teeth is necessary to preserve 
the fulness of the arch." 

The writer maintains the same opinion, but would add another reason, 
— viz., that the preservation, when possible, of the full size of the morsal 
surface of the teeth is important from the fact that if they are cut away 
the power of thoroughly grinding the food is by that much curtailed, and 
the child forms the habit of swallowing its food before it is properly 
masticated. 

EXCISION. 

In the operation of excision the diseased part is cut away with files, or with 
disks revolved by the dental engine, and the surface thoroughly polished. 
This operation is only admissible in the superficial stage of the disease. 
The advisability of the operation has been seriously questioned, however, 
by some of the best operators in the profession ; and in the light of the 
recent discoveries made by Williams in the modus operandi of enamel 
decay it would seem that the operation can be of very little benefit as a 
therapeutic measure. It may possibly retard the progress of the disease 
for a time by removing the roughened surface of the enamel, and thus 
making it a somewhat less favorable surface for the attachment of the 
zymogenic fungi, but as a permanent cure it is not to be relied upon, 



TREATMENT OF CARIES. 



173 



although every operator of experience has, no doubt, seen cases in which 
the operation has proved permanently curative. 

Many of the older operators, fifty years ago, practised the operation 
very extensively, and they were often quite successful in arresting the 
progress of the disease, but they did it at a great sacrifice of tooth-struc- 
ture. Approximal cavities in bicuspids and molars were often treated in 
this way, the method being to cut large Y-shaped spaces, the apex of the 
V at the cervices of the teeth, the base being so broad that the surfaces 
thus formed would be kept clean by the friction of mastication. 

Arthur at a later period (1871) introduced and extensively practised a 
modified form of the operation as a prophylactic as well as a curative 
method. 

He argued that the great majority of individuals suffered from proxi- 
mate caries of their teeth ; also that it was possible for the dentist by in- 
telligent observation to determine in advance those cases in which caries 
would occur. Observation had also taught that when the teeth were so 
arranged naturally that they were well separated from each other, -im- 
munity from caries was the general rule ; further, that the separation by 
filing, practised by the older dentists, often arrested the disease and gave 
immunity to such surfaces from further destruction ,• that accidental in- 
juries to the teeth which exposed the dentin, when in locations that were 
kept clean by the friction of mastication, and the practice of many abo- 
riginal races of filing their teeth for various purposes without injury 
to the dentin, led him to believe that the 
enamel might be removed without harm to 
the teeth, provided the surfaces and spaces 
thus made were of such shape that they 
could be readily cleansed. The friction of 
mastication and ordinary care on the part 
of the patient, he believed, would be suffi- 
cient to prevent the occurrence of the dis- 
ease. The method which he advised and 
practised was to separate the bicuspids and 
molars by means of thin corundum disks (Fig. 295), but as far as possible 
retaining the natural contour of the proximate surfaces. The six anterior 
teeth were separated by the same means, but in this case the separation 
consisted in forming V-shaped spaces upon the lingual surfaces, the apex 
of the V being directed towards the lip and the base towards the tongue. 

For a time this practice was followed by a considerable number of 
practitioners, but it gradually fell into disrepute from the fact that the 
claims of its advocate could not be realized by those who adopted it, 
except in a few isolated cases. 



Fig. 295. 




Corundum disks. 



CHAPTEE XII. 

TREATMENT OF GAMES (CONTINUED). 

The separation of contiguous or adjoining teeth, the proximate sur- 
faces of which may be the seat of caries, is an important and an essential 
procedure, preliminary to the operation of removing diseased tissue and 
restoring the tooth to its original form by the introduction of some suit- 
able filling- material. 

The enlarging of the interproximals space for a brief period is not 
only necessary, that a direct view of the cavity may be obtained, and 
facilitate the operation of cavity preparation, but that it may give oppor- 
tunity for restoring the original contour of the teeth with the filling 
material, so that when they return to their normal positions their relations 
to each other will be the same as before they were attacked by the carious 
process. 

Separation by filing is to be deprecated, and in these days it is rarely 
practised, as the restoration of contour is not possible by this method of 
separation. 

The resulting consequences from failure to restore the normal contour 
and mutual relationship of such teeth, particularly the bicuspids and 
molars, is often very serious. When permanent separations are made, 
either by filing or failure to restore the contour so that the approximal sur- 
faces do not "knuckle up" to each other, food is driven into the inter- 
proximate space, to the great annoyance of the patient and often painful 
and serious injury to the gum, inducing pericementitis, recession of the 
gum, and sometimes loss of the affected tooth. 

In dealing with the anterior teeth the restoration of contour is also 
important from the aesthetic stand-point. Teeth which have been perma- 
nently separated by filing present mutilations which in themselves con- 
stitute a deformity, while they often move out of their normal position by 
tilting towards each other, or assuming other positions out of harmony 
with the natural arrangement of the arch. 

The separation of the teeth is a procedure which calls for considerable 
care to avoid injury to the pericemental membrane and gum and to 
render the process as nearly painless as possible. There is considerable 
difference in individuals as to the amount of soreness and pain produced 
by separating the teeth. In children and young people the necessary 
space is gained much more quickly and with less irritation than when the 
alveolar walls have become firm and compact, or when the arch is full and 
the teeth are in close proximity. In the former the bone yields readily 
and permits an expansion of the arch, while in the latter the resistance to 
force is much greater and the process of expansion considerably slower. 
174 



TREATMENT OF CARIES. 175 

A certain amount of space is always gained, even in a full arch, by the 
closing of the slight spaces which often exist between the teeth. It is 
therefore important that the force applied and the materials or appliances 
used should be adapted to the conditions presented in each individual 
case. Constant and sustained pressure, if the force used is not too great, 
will separate the teeth more quickly and with less irritation than if applied 
intermittingly. With such precautious as would be suggested by good 
judgment no harm can come from the process, even when the tissues are 
irritable or the structures are of the firmest character. There is no diffi- 
culty in obtaining sufficient space for any operation if proper care is ex- 
ercised and the force is steadily and mildly applied. 

Methods of Separation. — Separations may be obtained by the em- 
ployment of various means, the selection of which should be governed by 
the conditions and requirements of the ease in hand, — viz., the amount of 
space required, the time in which it must be accomplished, the firmness 
and irritability of the structures, and the location of the teeth to be sepa- 
rated. 

Two methods are employed to gain space by wedging, one termed 
immediate or direct, the other gradual or indirect. 

Immediate or direct wedging is most applicable to the anterior teeth, 
where usually only a limited amount of space is required. Its greatest 
advantage, however, lies in its use as a method of obtaining space for the 
examination of the proximate surfaces, and to permit the introduction of 
polishing strips, for the removal of superficial softening of the enamel, 
stains and discolorations, and for the purpose of repolishing fillings. 

Immediate separation may be accomplished by forcing properly shaped 
wooden wedges between the teeth, either by steady jnessure or by driving 
with the mallet. The wedges should be made of hard, close-grained wood, 
orange- wood being the best. The wedges should be inserted between the 
teeth, one near the morsal edge, the other at the cervix, care being taken 
not to impinge upon the gum in such a manner as to bruise or otherwise 
injure it. These are then alternately forced farther and farther until the 
desired space is obtained. 

The angular form of the interproximate space sometimes makes it im- 
possible to use a wooden wedge, as the wedge travels towards the gum as 
soon as force is applied, instead of producing lateral pressure upon the 
approximal surfaces and insuring fixation of the teeth. 

Mechanical Separation. — Various mechanical appliances have been 
invented for the immediate separation of the teeth. The best for separating 
the anterior teeth is, no doubt, the one invented by Woodward, while 
those best adapted for gaining space between the bicuspids and molars are 
the Parr and the Perry forms (Pigs. 296 and 297). 

Separations made by the aid of these instruments for the examination 
of the approximal surfaces or to gain space for operations are far less 
painful than those obtained by driving the wooden wedge. They are also 
valuable for increasing the space gained by other methods, and for fixing 
the teeth which have been separated by the gradual method, and in which 
there still remains a little pericemental irritation and soreness. When 



176 OPERATIVE DENTISTRY. 

the patient is pressed for time it often becomes necessary to operate before 
the irritation has entirely subsided, but without some such support as this 
it would be impossible to operate, on account of the discomfort which 
would be caused to the patient, and which would be increased at every 
stroke of the mallet. 

Mechanical separators, however, have the disadvantage that they cannot 
be used in all locations, even if one possess a half-dozen or more different 

Fig. 290. 





Parr separator. Perry separator. 

forms, while with the Perry instrument there is a constant tendency for it 
to slip towards the gums. This can, nevertheless, be overcome by placing 
beneath the bows small pieces of gutta-percha or india-rubber. 

Parr's instrument is more universal, but it is decidedly more clumsy. 

Gradual or indirect wedging may be accomplished by the introduction 
between the teeth of thin wooden icedges, which should be changed to 
thicker ones each day, depending upon the swelling of the fibres under 
moisture to produce the separation. 

Linen tape, either waxed or unwaxed, is an admirable material with 
which to separate the teeth. 

Waxed tape will pass more readily between teeth that stand close 
together than will the unwaxed, but it does not move the teeth so quickly 
as the unwaxed, the wax preventing the rapid absorption of moisture and 
swelling of the fibres. It becomes necessary sometimes, however, to begin 
the separation by the immediate method, — either with a wedge of wood or 
the separator, — as it is inq>ossible to get anything between the teeth without 
the application of considerable force. As soon as sufficient space is gained, 
the tape may be inserted and the separating appliance removed. The tape 
should be removed each day and a thicker one inserted, until such time 
as the required space is obtained, when gutta-percha may be packed be- 
tween the teeth and allowed to remain until all soreness has disappeared. 
In fact, this or similar means of retaining the teeth in their separated 
position should always follow the removal of the material used for gradu- 
ally separating the teeth, as it is always best to wait for soreness to dis- 
appear before beginning the operation of filling. 

Pledgets of cotton may also be used as a means of separating the teeth, 
especially in the posterior teeth when the cavity has been broken through 
the morsal surface. The pledgets should be packed as tightly as possible 
when the cavity is not so deep as to involve a vital pulp. The cotton may 
then be saturated with sandarach varnish to bind the fibres together. 



TREATMENT OF CARIES. 177 

The front teeth may be separated with the same material by twisting 
it into a strand, drawing this between the teeth, and cutting the ends 
short. 

The cotton will act more rapidly, however, without the sandarach 
varnish, as this retards the absorption of water, and consequently the 
swelling of the fibres is more gradual. 

India-rubber — caoutchouc — in strips of various widths is perhaps, on ac- 
count of its effectiveness, more frequently used than any other means of 
producing gradual separation. When a strip of india-rubber is drawn 
between two teeth the middle portion is pressed to great thinness, the ends 
acting as two opposing wedges, the elasticity or resilience of the material 
constantly drawing the ends or wedges together until a space is obtained 
equal to the thickness of the strip. Great caution, however, should be 
exercised in using this material, as its power is very great, and serious 
pericemental inflammation may be induced by the use of strips which are 
too thick. 

Separations of almost any desired width may be obtained with this 
material, with little or no irritation, if only the strips used are thin enough 
and are changed every day. 

Red base-plate gutta-percha has been recommended by Bonwill as a de- 
sirable material with which to gradually separate the teeth. It should be 
packed firmly into the open cavities and existing space between the teeth, 
depending upon the force of mastication to produce expansion by driving 
the material towards the gum. 

This material is also valuable for exposing the cervical margins of the 
cavities which are covered by overlapping gum-tissue, by packing it into 
the cavity and interproxiraate space. It is much better than cotton for 
this purpose, as it does not absorb septic material. 

EXCLUSION OF MOISTURE. 

The exclusion of moisture during all operations upon the teeth is of the 
greatest importance. The presence of the oral secretions is often a serious 
obstacle to the performance of many operations, and when the flow is ex- 
cessive it becomes a matter of considerable annoyance to the patient. All 
operations upon the teeth are more successfully performed by the exclusion 
of moisture than when the mouth is flooded with its secretions ; but for 
the introduction of gold as a filling-material, and in the treatment of de- 
vitalized teeth, it becomes an absolute necessity. 

In the earlier days of modern dentistry the question of the exclusion 
of moisture during a long and tedious operation with cohesive gold caused 
the dentist many anxious thoughts, and added not a little to the nervous 
strain incident to his professional life ; a strain which the younger mem- 
bers of the profession can hardly realize or appreciate, since they are 
furnished with a material — the rubber dam — which removes entirely all 
anxiety upon the part of the operator that his operation may be com- 
pletely ruined by the entrance of moisture and his labor come to naught. 

Various methods and appliances have been introduced for the purpose 
of securing and maintaining dryness in the field of operation, including 

12 



178 OPERATIVE DENTISTRY. 

the napkin, bibulous paper, cotton pads, gauze, saliva ejectors, and the 
rubber dam. 

Napkins. — The use of napkins as a means of excluding moisture is the 
oldest, and was for many years the only one, with which the older practi- 
tioners daily fought the battle of maintaining a dry field for their opera- 
tions. It is still a valuable method, and is often resorted to in those cases 
in which the rubber dam cannot be employed, as, for instance, in the treat- 
ment of molars which are only partially erupted, or in those persons to 
whom the dam is so disagreeable or nauseating that they will not permit 
its use. 

Napkins for this purpose should be made of the best diaper or bird's- 
eye linen of various sizes, six inches, nine inches, and twelve inches square 
being the most useful sizes. The smallest ones folded in pads the full 
length of the napkin are admirable for use in the lower part of the mouth, 
and are applied by placing one end of it opposite the incisor teeth, be- 
tween the tongue and the lingual surfaces of the teeth, carrying the 
middle of the napkin to the angle of the jaw, folding it upon itself, and 
laying the other half between the cheek and the buccal surfaces of the 
teeth, and holding it in place with the thumb and index-finger of the left 
hand. If the tongue is raised before the napkin is applied upon the \\n- 

Fig. 298. Fig. 299. 





wmm 

Bicuspid napkin clamp. Molar napkin clamp. 

gual side of the teeth, the tongue will hold this end of the napkin in place, 
and at the same time press it down upon the orifices of the sublingual 
and submaxillary glands. A better means of holding the napkin in posi- 
tion is to apply the Ivory napkin clamp. (See Figs. 298 and 299). 

The larger napkins are folded by taking hold of one corner with the 
thumb and index-finger of the left hand and the lateral corners rolled or 
folded in. It is applied, for instance, to the upper left side by passing the 
corner held by the left thumb and finger under the lip at the left oral 
commissure, holding it there with the index-finger of the left hand, and with 
the index-finger of the right hand or a pair of dressing forceps carry the 
thicker part of the napkin backward to the tuberosity of the jaw ; then 
folding it upon itself, it is brought forward along the lingual surfaces of 
the teeth and maintained in its position with the left index -finger. The 
free end of the napkin is then spread out so as to cover the lower lip. 
The procedure for the right side is the same, with the exception that the 
hands are reversed. 

Bibulous paper, prepared gauze, and cotton pads are now used by some 



TREATMENT OF CARTES. 179 

operators to the exclusion of napkins. Their application is similar to 
that of napkins folded into pads. 

The moisture which appears around the necks of teeth, coming from 
the glands at the margin of the gums, is often quite troublesome when only 
the napkin or similar means are used to exclude the moisture. This may 
be controlled by packing small pieces of bibulous paper between the teeth 
at the cervix. 

Saliva Ejectors. — These instruments are exceedingly useful in con- 
junction with napkins, bibulous paper, etc., or with the rubber dam, for 
removing the secretions that accumulate during the operation. In many 
operations the necessary position of the jaws is such as to make it impos- 
sible for the patient to swallow, hence the accumulation of saliva is often 
very troublesome to both the patient and the operator, especially so when 
the secretions are normally excessive, or are greatly increased by the 
stimulation of operative procedures. These instruments act upon the 
principle of the siphon, and are made for attachment to the water-supply 
and used in connection with the fountain cuspidors. 

Rubber Dam. — Barnum conferred a great boon upon suffering humanity 
and greatly lightened the labors of the dentist by his invention of apply ^ 
ing sheet-rubber or rubber dam as a means of excluding moisture from 
the field of dental operations, thus making it possible to save many teeth 
which before were condemned to the forceps. It has universal applica- 
tion in all parts of the mouth wherever a tooth or root has sufficiently 
emerged from the gum for the dam to be passed over it. 

It is of greatest value, however, in the preparation and filling of 
proximal cavities where the disease has extended beneath the gum, and 
in which the exclusion of the secretions and of blood is a difficult matter 
with any other means at our command. For the exclusion of moisture 
and septic secretions, and the protection of the soft tissues from medica- 
ments in the treatment of devitalized teeth, alveolar abscesses, etc., it is 
indispensable. 

Rubber dam is made in three thicknesses, known as thin, medium, and 
thick, and usually sold in strips varying in width from five to seven inches. 
The preference for general use lies with the medium thickness, although 
it is well to have all three thicknesses on hand. The quality of the rub- 
ber is a matter of first importance ; it should be strong, elastic, extensible, 
and free from odor. Exposure to the atmosphere and the high tempera- 
tures of summer weather cause deterioration in these qualities and soon 
render it worthless. To protect it as much as possible from these deterio- 
rating influences it is usually sealed in tin cans or boxed. It should be 
cut for use into squares and triangular pieces, the squares from five to seven 
inches, the triangular pieces being made by folding the squares corner- wise 
and dividing them. A form of rubber dam has lately been introduced 
which is coated with a metallic aluminum powder, which gives it a very 
light appearance and adds greatly to its usefulness by making it luminous. 
The application of the rubber dam is to the student in his first attempt to 
adjust it a somewhat difficult procedure ; to the older practitioner who has 
become expert by long practice it is usually a simple matter, requiring 



180 



OPERATIVE DENTISTRY, 



but a moment of time ; and yet occasionally a case will present in which 
its application will require all his ingenuity and patience. 

In adjusting the dam to a tooth with a simple cavity upon the morsal 
surface, a hole should be pinched or cut at such a location as will permit 
the dam to lie smoothly over the mouth after its adjustment to its position. 
The dam may be adjusted by grasping the two upper corners with the 
thumb and index-finger of both hands, and with the middle finger of 
each hand placed on opposite sides of the hole through which the tooth is 
to pass, the rubber is put on the stretch. This enlarges the hole in the 
rubber, and it is forced over the tooth by passing first one edge and then 
the other of the opening between the mesial and distal proximal spaces, 
and carrying it well up to the cervix. Fig. 300 shows the rubber dam in 
position upon the upper incisor teeth, the upper corners of the dam being 



Fig. 300. 



Fig. 301. 





Rubber dam applied. 



Rubber-dam bolder. 



secured with a rubber-dam holder (Fig. 301) Various other forms of 
holders are also for sale by the dealers, and the operator may suit himself 
with almost any desired form. The rubber dam may be held smooth by 
attaching weights to the lower corners. 

If two or more teeth are to be isolated, it then becomes necessary to 
punch the same number of holes in the dam, so locating them that when 
the dam is placed in position the straits between the holes will be just a 
trifle wider than the spaces between the teeth ; the edges of the dam 
around the cervices of the teeth should then be turned under, using the 
point of any straight-pointed instrument of suitable size. The dam thus 
grasping the cervix of the tooth acts as a valve, and effectually excludes 
all moisture from the teeth so enclosed. To secure the dam in position, a 
ligature may be passed around each tooth and tied with the surgeon's knot, 
or clamps of various forms (Fig. 302) are used alone for the same purpose, 



TREATMENT OF CAEIES. 



181 



or in conjunction with the ligatures. Properly constructed clamps are 
so shaped that they materially assist in holding the dam away from the 
crown of the tooth, thus causing less obstruction to the entrance of light 



Fig. 302. 




Ivory's clamps. 

and giving a better view of the field of operation. The Ivory clamps 
possess these very desirable features to a greater extent than any others at 
present known to the writer. 

Fig. 303. 




>*v- 

The Ottolengui clamp applied 




The Ottolengui clamp (Fig. 303) also possesses many of the desirable 
features. 

Fig. 304. 




Dr. How's cervix screw clamp. 

The How cervix screw clamp (Fig. 304) is an admirable instrument for 
securing the dam and exposing the cervical margin in cervical cavities. 
Its application is shown in the illustration. 



182 



OPERATIVE DENTISTRY. 



Specially constructed forceps are necessary in the adjustment of all 
forms of spring clamps like those shown in the preceding illustrations. 

Fig. 305 shows a method of adjusting the clamp and the rubber dam at 
the same time. The clamp in the illustration is known as the Elliot molar 
clamp, and is a favorite appliance with many operators. 



P 



Fig. 305. 




Elliot's clamp and forceps 



When the teeth are very close together and the alveolar walls are very 
firm, it is sometimes a difficult matter to pass the dam between the teeth 
without some special preparation of the contiguous surfaces. The rubber- 
dam applier, shown in Fig. 306, duplicates the fingers and materially 



Fig. 306. 




Rubber-dam applier. 

assists in forcing the dam between the teeth. In all such cases the passage 
of the dam may be facilitated by first lubricating the surfaces by passing 
floss-silk between them which has been charged with vaseline, cosmoline, or 
toilet soap. 

The holes in the dam may be made either with the punch (Fig. 307), 
the scissors, or by stretching the dam over the end of a small, round. 

Fig. 307. 




Ainsworth's rubber-dam punch. 

tapering instrument, 

purpose, — and nicking the rubber near the point with a sharp knife ; the 

result is a perfectly round hole. Any desired size may thus be obtained ; 



TREATMENT OF CARIES. 



183 



the lower down upon the instrument the nick is made the larger the hole ; 
the tighter the dam is drawn the smaller the hole will be. 

The writer has used this method many years, to the exclusion of all 
others, and with perfect satisfaction. 

Fig. 308 shows the relative size of holes adapted to (1) incisors and 
cuspids, (2) bicuspids, (3) molars. The depressed rubber dam (Fig. 309) 



Fig. 30S. 



Fig. 309. 




:: ■ -f? "■ 




and the Denham coffer-dam shield (Fig. 310) are often found useful in 
operations for children and in preliminary treatments, or when remedies 
are to be used which it is desirable should not come in contact with the 
surrounding tissues of the mouth. Fig. 311 shows the Denham coffer-dam 
shield adjusted and secured with a clamp. A small mirror (Fig. 312) 
may be inserted in the depressed rubber dam for the purpose of greater 
illumination. 

Fig. 310. Fig. 311. 




Denham coffer-dam shield. 
Fig. 312. 




Mirror. Denham coffer-dam shield adjusted. 

Nausea and other unpleasant symptoms are often occasioned by the 
contact of the rubber dam with the tongue and palate, and from the un- 
pleasant odor. The nausea may be relieved by spraying the mouth and 
throat with a two per cent, solution of cocaine in water, while the un- 
pleasant odor may be overcome by dipping the dam in rose-water or other 
toilet- water. Jack recommends painting the parts with tincture of cam- 
phor, while the nervous conditions which sometimes appear on adjusting 
the dam and covering the mouth may be overcome by requesting the 
patient to breathe freely through the nose. 



CHAPTEE XIII. 



HYPERSENSITIVE DENTIN. 



Dentin is a fibro-caleareous structure, tubular iu character, the tubuli 
passing from the pulp-chamber to the periphery of the dentin, branching 
in their course, and terminating in minute tubules, which unite to form an 
intricate plexus. These tubuli are each of them traversed by a minute 
fibril or filament, which is generally thought to be a prolongation of an 
odontoblastic cell, and that through these fibrils sensation is conveyed to 
the dental pulp. There is some evidence, however, as already pointed 
out in Chapter III., that a portion of the tubuli are occupied by certain 
fibres, which appear to be prolongations of the nerve-filaments of the pulp, 
or that the nerve- filaments of the pulp enter the odontoblasts, and thus 
furnish the necessary elements which fit the fibrillar to carry sensation. 

It has never been demonstrated, however, that the fibrillar of the dentin 
were composed of nerve-tissue, and yet there can hardly be a doubt that 
such is their composition, for they perform the functions and present all 
the phenomena of nerve-tissue under stimulation and under irritation. 

Dentin in its normal state is only slightly sensitive, but when subjected 
to irritation from external agencies it may become most excruciatingly 
hypersensitive. The degree of hypersensitiveness will depend upon the 
character of the irritant, the point of attack, its duration, the condition 
of the oral secretions, the character of the structural development of the 
teeth, the age, and the physical condition of the patient. 

Irritation from caries is the most common cause of hypersensitive dentin, 
the degree of abnormal sensitiveness depending largely upon the char- 
acter of the carious process. In the white or rapid form of caries the 
hypersensitive condition is usually the most exalted. In the brown or less 
rapid form the sensitiveness is much less, while in the black or slow form 
it is but little above that of normal dentin. 

The most sensitive part of a carious tooth is just beneath the protecting 
enamel or cementum, on the periphery of the dentin at the terminal ends 
of the fibrillar, just as the most sensitive part of the external surface of the 
body lies immediately beneath the horny layer of the cutis at the termina- 
tions or end organs of the nerves. It therefore becomes evident that caries 
in the superficial stage will present the highest degree of hypersensitive- 
ness to be found in each of the three forms of caries. In other respects 
the zone of greatest sensitiveness is directly beneath the softened portion 
of dentin, the sensitiveness becoming less and less as the sound tissue is 
approached. 

Another cause of hypersensitive dentin is irritation from attrition or 
mechanical abrasion. This cause, however, operates so slowly that certain 
184 



HYPERSENSITIVE DENTIN. 185 

changes may take place in the dentin within the tubuli "by the deposition 
of calcific deposits, — eburnation, — which after a time diminishes or entirely 
destroys their capacity to convey sensation. The same process of eburna- 
tion sometimes takes place in chemical abrasion and denudation, thereby 
lessening and sometimes entirely obliterating sensation. 

Exposure of the cementum from recession of the gums is another very 
common cause of hypersensitive dentin, but here again nature is prone to 
mitigate the conditions by the same calcific changes in the dentinal tubuli. 
But caries often supervenes in these cases from lack of attention upon the 
part of the patient, who, because of the pain induced by the use of the 
brush, fails to keep these surfaces properly clean. There is also very 
often the added influence of acid mucous or salivary secretions, which by 
their irritating effect tend to augment the hypersensitive condition, while 
the reverse is true when the oral secretions are alkaline or neutral. 

Excessive sensibility of the teeth is often an accompaniment of the 
catamenia, of dyspepsia, neuralgia, pregnancy, pulmonary tuberculosis, 
especially in its later stages, typhoid fever, acute rheumatism, and the 
convalescent stage of fevers in general. The condition under these circum- 
stances is due to the changed or vitiated character of the oral secretions, 
which have almost invariably a strongly acid reaction. 

Imperfect calcification of the teeth is another factor in the etiology of 
hypersensitive dentin. The teeth of children and of rapidly growing 
young people are, as a rule, much more sensitive than those of adults. 
This is thought to be due to the fact that the teeth during childhood and 
youth are still undergoing changes of development, and that they are not 
all fully formed, in the sense of being perfectly calcified, until adult age ; 
but that as each group of teeth are perfected they become less susceptible 
to external irritants, and consequently less sensitive. Females, however, 
as a general rule, are more often sufferers from hypersensitive dentin than 
are males. 

Nervous irritability is greater in some persons than in others, females 
usually possessing a larger share than males, and this in a measure accounts 
for the intense suffering which some of these individuals endure from 
hypersensitive dentin. This exalted irritability of the nervous system in 
some instances is only a passing condition which has developed as the 
result of illness, mental or physical shock, overwork of mind or body, 
over-indulgence in social pleasures, or of debauchery ; while in other in- 
stances it is an established condition or dyscrasia peculiar to the indi- 
vidual ; or it may be a family peculiarity which has been transmitted as 
an inheritance. In any event the suffering is so great in some of these cases 
of hypersensitive dentin as to call for the greatest sympathy, considera- 
tion, and forbearance upon the part of the operator during the preparation 
of the cavity. The dentist who cannot rise to such an occasion, and by 
tenderness and sympathy endeavor to carry the patient through the trying 
moments of the ordeal without losing his patience, should change his 
occupation, as he lacks or has lost the most important qualification for a 
successful dental practitioner. 



186 OPERATIVE DENTISTRY. 



TREATMENT OF HYPERSENSITIVE DENTIN. 

The treatment of hypersensitive dentin is one of the most perplexing 
problems with which the dentist has to deal, and consequently the reme- 
dies which have been suggested and introduced from time to time for ob- 
tunding the sensation of dentin have been legion. Each new remedy has 
generally been extolled as a specific ; but each of them, after a few trials, 
has been laid aside, with the hopes that were from the beginning doomed 
to disappointment. Specific medication succeeds no better in the treat- 
ment of dental diseases than it does in general medicine. Certain remedies 
which may cure in one case often prove only an aggravation in another, 
and remedy after remedy may be tried with no appreciable beneficial 
effect ; while, upon the other hand, certain drugs have been found which 
will upon their application to the dentin positively destroy its sensation, 
but will also destroy or jeopardize the vitality of the pulp. 

The treatment of hypersensitive dentin is therefore limited to those 
remedies and procedures which will temporarily relieve or mitigate the 
suffering incident to the preparation of cavities, or to give permanent 
relief in the various other forms of irritation to which the vital dental 
tissues are subjected. 

Treatment of Moderate Hypersensitiveness. — In the treatment 
of moderate hypersensitiveness due to caries the excavation of the cavity 
should be approached in a manner to engender confidence upon the part 
of the patient that the operator will endeavor to perform his task with the 
least possible pain and in the most expeditious manner that the nature of 
the case will permit, assuring the patient that, if the pain is unbearable, 
palliative means shall be employed for its relief. With such assurances, 
accompanied with a calm, cheerful, and sympathetic manner upon the part 
of the operator, the courage of the patient can usually be stimulated to such 
a degree that the operation may be completed without resort to obtunding 
agents. 

By a display of harshness in the methods of operation, or an exhibition 
of irritability of temper, or an unsympathetic mood upon the part of the 
operator, apprehension, dread, and nervous excitement are increased, and 
the difficulties of controlling the patient by just that much augmented. 

It is often advisable in dealing with nervous individuals, either adults 
or children, to select for the first operation something that will cause little 
or no pain, that they may become acquainted with the various surround- 
ings and procedures incident to dental operations. This will relieve their 
dread and apprehension for the time, and thus make it possible to advance 
by degrees from the simpler and comparatively painless operations to the 
more complicated and severer ones. 

In excavating the simpler cases of moderately hypersensitive dentin, 
sharp instruments only should be used, but these should never be sharp- 
ened in the presence of the patient, for reasons which are obvious. The 
cutting should be done by quick, light, and sure movements, as such cut- 
ting is decidedly less painful than slow, heavy, scraping movements of the 
instrument. The direction of the cutting should, for the same reason, 



HYPERSENSITIVE DENTIN. 187 

always be from the centre of the cavity towards the periphery, and never 
towards the pulp. If burs driven by the dental engine are used, these 
should be sharp and clean -cutting, as dull burs, or those which clog and 
do not cut freely, engender heat by friction, and thus increase the pain 
incident to the operation. 

If the bur be revolved at a high rate of speed, and the contact with the 
sensitive dentin made by light, quick touches, this tissue may be removed 
with so little pain as to be quite tolerable. The dread, however, of the 
dental engine has been induced by the reverse of this method of operating. 

If the operator prefers to prepare the cavity in the moist state, it will 
be found that if a continuous stream of warm water be thrown into the 
cavity while excavating with the bur, the pain will be greatly mitigated. 
On the other hand, if the dry method be adopted, it will be found that 
the more nearly complete desiccation is obtained the less will be the pain 
experienced. 

In those cases in which the hypersensitive condition is so great as to 
render the operation of cavity preparation by the foregoing methods in- 
tolerable, treatment, either local or constitutional, must be instituted to 
temporarily mitigate or palliate the suffering. This treatment may con- 
sist of the exhibition of certain therapeutic remedies, chemical agents, or 
anaesthetics, either local or general. 

PALLIATIVE TREATMENT. 

The treatment of the hypersensitive dentin by palliating remedies 
applied locally is sometimes beneficial in relieving the pain of excava- 
tion. The available drugs for this purpose are niorjmia, veratria, atropia, 
cocaine, cannabis indica, and chloretone. As neither of these remedies 
produces any immediate effect, it is customary to seal them in the cavity 
— after the thin enamel edges have been removed and the softest portions 
of the decayed dentin have been lifted out — with gutta-percha or zinc 
oxyphosphate for two or three days or longer, when on removing the 
temporary filling it will be found that the hypersensitive condition has 
been materially lessened. 

Morphia sulphas and morphia acetas are both used for this purpose, but 
the writer prefers the acetas, as it seems to give the best results. 

To prepare the morphia for this purpose it should be rubbed up in 
glycerol, an eighth of a grain of morphia to a drop of glycerol. The 
cavity should first be neutralized by irrigating it with an alkaline solution, 
preferably sodium bicarbonate. The rubber dam should then be adjusted, 
the cavity dried, and the morphia paste carried into the cavity and spread 
over its walls, after which the temporary filling should be introduced. 
The writer prefers the zinc oxyphosphate, for the reason that by mixing it 
soft it can be introduced without pressure, and this is an important advan- 
tage in those cases in which the dentin is exceedingly sensitive. 

Veratria is prepared in the same manner,— one-twentieth of a grain in 
sufficient glycerol to make a thin paste, — spread over the surface of the 
cavity, and sealed in with cement The veratria acts by producing paraly- 
sis of sensation in the dentinal fibrillar 



188 OPERATIVE DENTISTRY. 

Atropia sulphas, one- sixteenth of a grain, may be prepared and intro- 
duced in the same manner and often with good results. Atropia applied 
locally relieves pain and sensitiveness by its paralyzing effect upon the 
peripheral nerves, and doubtless acts in the same manner upon the denti- 
nal fibrillse. 

Cocaine citras and hydrochloras, one-eighth of a grain in glycerol, ap- 
plied as above, sometimes prove efficacious in overcoming the sensitiveness 
producing local anaesthesia of the dentin. 

Cannabis Inclica — fluid extract — applied upon cotton and sealed into 
the cavity will also sometimes give relief. 

Chloretone is perhaps the most efficient remedy for this purpose that has 
as yet been introduced to the profession. It is employed in solution as a 
local application to hypersensitive dentin. The solution is made by mix- 
ing equal parts by weight of sulphuric ether and the crystals of chloretone. 

The chief objection to the use of these remedies is the great length of 
time which is required for them to act. This is explained by the exceed- 
ingly small amount of organic material in the dentin and the low absorp- 
tive powers possessed by this tissue. 

Constitutional palliative treatment consists in the exhibition of such 
drugs as, by their sedative and analgesic action, will measurably obtund 
general sensation for a short period of time. These are morphia, chloral 
hydrate, potassium bromide, and whiskey combined with some of them 
for its stimulating effect. 

The following formulae have been found by the writer to be very useful 

for this purpose : 

R Morphia sulph., gr. J ; 
Bourbon whiskey, f 5 i. 
Sig. — Twenty minutes before operation. 
For an adult. 

R Croton chloral hydrate, gr. x ; 
Bourbon whiskey, f §i. 
Sig. — Thirty minutes before operation. 
For an adult. 

R Potassium bromide, gr. xx to xxx ; 
Cinnamon- water, f§i. 
Sig. — Thirty minutes before operation. 
For an adult. 

R Potassium bromide, gr. xv to xx ; 
Croton chloral hydrate, gr. x ; 
Cinnamon-water, fgi. 
Sig. — Thirty minutes before operation. 
For an adult. 

CHEMICAL TREATMENT. 

The treatment of hypersensitive dentin by chemical agents includes 
the application of caloric by means of heated air and such coagulants as 
carbolic acid, zinc chloride, caustic potassa, chromic acid, nitric acid, and 
silver nitrate. Arsenic and cobalt have also been recommended for the 
purpose of obtunding hypersensitive dentin, but the dangers which are 



HYPERSENSITIVE DENTIN. 189 

likely to follow their use— viz., of destroying the vitality of the pulp and 
ultimately producing discoloration of the tooth — should render the exhibi- 
tion of these drugs for such a purpose entirely inadmissible. 

Heated Air. — This means of obtunding hypersensitiveness of the den- 
tin was first suggested by Brockway * (1872). It is perhaps the most gener- 
ally efficient and safest means by which the dentin may be temporarily 
deprived of its sensation. The therapeutic effect is produced by the 
abstraction of a portion of the water contained in the dentinal tubuli, or, 
in other words, by a partial dehydration, which renders the dentinal 
fibrillar less capable of transmitting sensation. Were it possible to com- 
pletely dehydrate the dentin, complete suspension of sensation would be 
the result. More or less complete dehydration of the exposed surface of 
the dentin can be accomplished, but this process cannot be carried to any 
considerable depth, neither is it necessary, for usually the hypersensitive- 
ness is markedly relieved under a partial dehydration of the exposed 
surface. 

In using this means of obtunding hypersensitive dentin the rubber 
dam should always be used, first, to exclude the outside moisture, and 
secondly, to protect the soft tissues from the heated air. 

Fig. 313. 

Hot-air syringe. 

The cavity is then dried with bibulous paper and pellets of amadou, 
after which the heated air may be thrown into the cavity from one of the 
variously formed air syringes. Fig. 313 represents the ordinary form of 
warm-air syringe, the cylinder of which is heated over an alcohol flame 
or a Bunsen burner. This cylinder contains a carbon core which greatly 
increases its heating power, and thus by means of the rubber bulb a con- 
tinuous stream of heated air can be 

carried through the nozzle into the Fig. 314. 

cavity. Another form of syringe, in- 
vented by Dr. S. G. Perry, is shown 
in Fig. 314. Care is necessary in the 
use of this instrument not to cause 
pain by overheating the surface of the p err y hot-air syringe. 

dentin. The blast of air first thrown 

into the cavity should not be above a degree of heat that would be toler- 
ated by the unprotected skin upon the back of the hand. In fact, the 
writer always tests the degree of heat to be first applied in this manner. 
As the process of dehydration goes on, the heat may be gradually increased 
until a degree can be painlessly used that could not be tolerated by the 

* Dental Cosmos, vol. xiv. p. 19. 





190 OPERATIVE DENTISTRY. 

skin. A certain amount of skill lias to be obtained in order to direct the 
blast of heated air in such a manner as to cause the least pain when it comes 
in contact with the hypersensitive dentin. If the nozzle of the syringe 
is held too far away from the cavity, the heated air in passing through the 
surrounding atmosphere becomes cooled and thus causes pain ; while, upon 
the other hand, if it is held too near, the blast is liable, by its high degree 
of heat, to cause equally severe pain. In applying heated air it is best to 
begin gently with a single short blast, repeated at intervals of a few sec- 
onds, but as dehydration progresses the length and force of the blast may 
be increased and at shorter intervals until the pain ceases. 

Fig. 315. 




Improved electric hot-air syringe. 

Another instrument for this purpose is shown in Fig. 315. This 
syringe has a glass nozzle in which is a spiral loop or platinum wire, con- 
nected by flexible copper cords to a low voltage electric current. The 
platinum loop can be heated to any degree desired, and by pressure upon 
the rubber bulb attached to the opposite end of the instrument a con- 
tinuous stream of air is made to pass over the heated loop and through 
the nozzle. To protect the lips from being burned with the hot nozzle 
it is covered with a perforated metal shield. With this instrument it is 
possible to maintain an even degree of heat for any length of time, and 
this is a very great advantage. 

Some operators prepare the cavity for dehydration with heated air by 
first wiping it out with absolute alcohol, as this has a strong affinity for water. 

In severe cases of hypersensitiveness which the employment of heated 
air does not relieve, and such cases are not infrequently met with, the 
crystals of carbolic acid may be applied to the cavity and followed by the 
heated air blast, at short intervals, for two or three minutes. This treat- 
ment will, in many cases, give complete relief, and yet it cannot always 
be relied upon to do this. 

Carbolic Acid. — This remedy when used alone has but very little im- 
mediate effect in obtunding hypersensitive dentin, but when used as above 
suggested, or when combined with oil of cloves in the proportion of two 
parts of carbolic acid to one of oil of cloves, its efficiency is increased. 
Both carbolic acid and oil of cloves have slightly local anaesthetic proper- 
ties, but when combined, this property seems to be greatly increased. 
Carbolic acid also coagulates albumin, and this property may effect the 
conducting power of the fibrils with which it comes in contact. 

The best results, however, are obtained with this combination by seal 



HYPERSENSITIVE DENTIN. 191 

ing it into the cavity with zinc oxyphosphate cement for three or four 
days. 

Carbolic acid combined with tannic acid to form a thin paste is many 
times of service in treating these cases, if allowed to remain in the cavity 
for a few days. In applying this combination the cavity should be lined 
with the paste and sealed in with zinc oxyphosphate cement. 

Zinc Chloride. — This is one of the oldest and possibly the most effi- 
cient local remedy for obtunding hypersensitive dentin in the whole arma- 
mentarium of the dentist. It must, however, be used with the greatest 
caution and good judgment, on account of its escharotic action and its 
irritating effect upon the dental pulp. It should, therefore, be interdicted 
in all deep cavities, and under no circumstances placed in close proximity 
to a living pulp, if it is desirable to conserve its vitality. 

The therapeutic action of zinc chloride is due to its affinity for water 
and its coagulating properties upon albumin, both of which have an ob- 
tunding effect upon the dentinal fibrillar. 

When using zinc chloride the rubber dam is indispensable, and it 
should be so adjusted that there will be no possibility of leakage of fluids 
from the mouth into the cavity, or of the zinc chloride coming in contact 
with the soft tissues of the mouth. After drying the cavity in the ordi- 
nary manner, the zinc chloride is applied upon a pledget of cotton to the 
walls of the cavity, and allowed to remain in position for five or ten 
minutes, or until pain ceases. As soon as this stage has arrived the opera- 
tion of excavation may be entered upon. It is best, however, to remove 
the excess of the zinc chloride first by drying with bibulous paper, and 
then to irrigate the cavity to terminate the action of the agent, as its 
strong affinity for water quickly deprives the tissue of any remaining 
portion. Its coagulating effect upon albumin prevents it from penetrating 
to any considerable depth, and therefore makes it a comparatively safe^ 
remedy to employ in all but deep-seated cavities, or when the pulp is nearly 
exposed. 

The pain is often inteuse for a few moments after the introduction of 
this remedy into the hypersensitive cavity, but this gradually subsides, 
and usually in a few minutes entirely passes away. If, however, the pain 
continues, it may sometimes be controlled by the application of heated air, 
or of carbolic acid, or of both combined. Its greatest sphere of usefulness 
is in the superficial cavities at the labio- and bucco- cervical margins of the 
incisors, cuspids, and bicuspids. When employing it in the approximal 
cavities of the incisors, especially in children whose age would indicate 
that the process of calcification was not fully completed, caution should 
be exercised not to cause irritation of the pulp, as the cornua in these 
cases often lie quite near to the surface. 

Occasionally cases will be found in which this agent does not seem to 
act with any immediate effect ; but if the excess of the agent be removed 
with bibulous paper, and the cavity dried as thoroughly as may be by this 
means, and then closed with gutta-percha or zinc oxyphosphate, it will be 
found that in two or three days the carious dentin can be removed without 
pain, or only such slight sensations as are readily tolerated by the patient. 



192 OPERATIVE DENTISTRY. 

Zinc chloride, to be most efficient, should be chemically pure. The 
fused form is the best, and this should be liquefied by the addition of just 
sufficient distilled water to produce this effect, It should be kept in a 
tightly stoppered bottle, as the drug has such an affinity for water that it 
will abstract it from the atmosphere. 

Some operators prefer to obtain the obtunding effect of the zinc chloride 
by filling the cavities with zinc oxyekloride, and allowing it to remain for 
a few weeks, when the hypersensitive condition will have been greatly 
lessened or have entirely disappeared. In this cement there is usually an 
excess of the zinc chloride which has not combined with the oxide, and 
as a consequence it is free to act upon the organic matter in the dentin. 
This method is, however, inadmissible in all deep cavities in vital teeth, 
for the reasons already mentioned. 

Caustic Potassa. — Caustic potassa combined with carbolic acid in 
equal parts (Robinson's remedy) often serves a good purpose in obtunding 
hypersensitive dentin. The rubber dam should be applied to protect the 
soft tissues, and the remedy introduced upon a pledget of cotton. This 
often causes sharp, stinging pain, which usually subsides in a few moments. 
Its obtunding action is increased by the application of a blast of heated air. 

Chromic acid and nitric acid have both been recommended as obtundents 
of hypersensitive dentin. Their escharotic action is so great, however, as 
to make them dangerous agents to use, while their decalcifying effect upon 
tooth structure is so strong that great care must be exercised to counteract 
this effect by the use of alkaline solutions immediately afterwards. The 
soft tissues should be protected from injury by the rubber dam, and the 
agents introduced into the cavity by means of a platinum- or gold-pointed 
instrument. These agents are only admissible in very shallow cavities, 
for the reasons just stated. Chromic acid acts by coagulating the organic 
elements of the dentin, while nitric acid decomposes the tissue. . 

Silver nitrate is used for obtunding hypersensitiveness of the dentin in 
superficial cavities and cervical hypersensitiveness resulting from recession 
of the gums, but it is not admissible except in the posterior portion of the 
mouth, where the black discoloration produced by it would not be objec- 
tionable. Two, and sometimes three, applications are necessary to en- 
tirely obtund the sensation. Moisture should be excluded, and the soft 
tissues protected during its application. A fifty per cent, solution of the 
drug is applied to the cavity or the sensitive part of the tooth upon a 
pledget of cotton, and allowed to remain in contact for a few moments, 
after which the excess may be removed with bibulous paper and the parts 
irrigated with water. 

Local anaesthesia of the dentin may be produced by ether or rigolene 
sprayed upon the tooth, but, as a rule, the pain produced in the early 
stages of the process by the intense cold is often greater than the pain ex- 
perienced in operating upon the hypersensitive dentin in its original state. 
The danger also exists in treating these cases by this means, of producing 
inflammation, and finally devitalization of the pulp through the irritation 
of such severe thermal shock. 



CHAPTER XIV. 

CATAPHORESIS. 

Cataphobesis, electric osmosis, and electric transfusion are terms 
which have been applied in electrophysics to certain phenomena, by 
which the direct or galvanic current of electricity seems to convey fluids 
and chemical substances in solution through animal membranes and tissues, 
and deposits them at the poles. 

The physical phenomena of natural osmosis, whereby fluids of unequal 
density pass through animal membranes and tissues in a direction from 
the lighter to the denser fluid, illustrates the process of cataphoric action. 
If two fluids of unequal specific gravity be separated by an animal mem- 
brane, and the positive pole or anode of the galvanic current conveying 
ten to fifteen milliamperes be placed in one, and the negative pole or 
cathode in the other, it will be found that the fluid in contact with the 
anode will rapidly decrease in quantity, while that in contact with the 
cathode will be increased in volume. This is, however, seemingly some- 
thing more than simply the natural physical phenomena of osmosis, accel- 
erated by the action of the electric current, for the direction of the move- 
ment of the fluid is controlled by the positive current,— viz., it flows from 
the positive to the negative pole. But if the current be reversed the 
volume of the fluid is changed at once by the denser fluid being carried 
into the partition containing the lighter fluid, thus reversing the estab- 
lished order of the movement of fluids in natural osmosis, and this phe- 
nomenon may be produced again and again at the will of the experi- 
menter. 

This power of conveyance of chemic elements possessed by the direct 
current is not confined to substances of elementary form, but may in many 
instances be applied to substances of very complex chemic structure, as, 
for instance, cocaine (C 17 H 21 N0j, or methyl-blue (C ]6 H 18 Nj,SCl) , which may 
be conveyed as molecules. On the other hand, certain chemic substances 
may be conveyed through animal membranes and tissues, but on coming in 
contact with the opposite pole are decomposed by the electrolytic action 
of the current and the radicles or individual elements set free. 

For instance, if a pellet of absorbent cotton saturated with a neutral 
solution of potassium iodide (KI) be placed upon the cathode, another 
piece of cotton soaked in distilled water be placed upon the anode, a 
piece of animal membrane, like chicken-skin, be placed between them in 
contact with the cotton upon each electrode, and a current of from ten to 
fifteen milliamperes be made to pass for about fifteen minutes, no change 
will be noticed at the cathodal electrode, but the cotton at the anode and 
the surface of the membrane lying in contact with this pole will be found to 
be slightly colored with iodine. 

13 193 



194 OPERATIVE DENTISTRY. 

This seems to prove, first, that the potassium iodide travels under the 
influence of the direct current from the negative to the positive pole, and 
secondly, that in all probability this chemic compound is conveyed through 
the membrane in a molecular form as potassium iodide, and upon reaching 
the anodal electrode is decomposed by the electrolytic action of the current, 
and the iodine is set free. On the other hand, if the potassium iodide 
solution be placed at the anodal electrode, the cotton at the cathode be 
soaked with distilled water only, and a current be turned on of the same 
strength and for the same length of time, no change will be observable in 
the color of the cotton at the cathode, nor of the cathodal surface of the 
membrane, while at the anode the cotton will be deeply stained with 
iodine. 

In illustration of the conveying power of the direct current applied to 
the more complex chemic compounds, cocaine (C 17 H 21 !N"0 4 ) may be taken 
as a fair sample of these compounds. 

If a four per cent, solution of cocaine hydroehlorate be placed in contact 
with the surface of the skin by means of absorbent cotton, disks of 
blotting-paper, sponge, or other absorbent material, it will have little or 
no effect in obtuuding sensation, although it may be kept in contact for an 
hour or more. Let this same solution, however, be applied in the same 
manner, and then pass a direct current of from fifteen to twenty milli- 
amperes through the tissues, the anode being placed in contact with the 
substance containing the cocaine solution and the cathode at some other 
point, the cuticle in the region of the anode will in a very short time be 
found to be thoroughly anaesthetic, and will remain in this condition for 
from several minutes to as many hours, the period of anaesthesia depending 
upon the strength and density of the galvanic current employed, the dura- 
tion of its application, and the per cent, of the cocaine solution which had 
been applied. 

Another simple experiment illustrating the conveying power of the 
direct current is made with methyl-blue. Take two open-mouthed jars 
having the capacity of one or two quarts. Half fill each of these jars with 
distilled water, adding a small quantity of methyl-blue, sufficient to slightly 
tint the water. Then place the anode in one jar and the cathode in the 
other. If the right hand be now immersed in one jar and the left in 
the other, thus completing the current, and be permitted to remain for 
twenty minutes, while a current of ten to fifteen milliamperes is allowed 
to pass through the circuit, it will be found at the expiration of this period 
that the hand which had been placed in the jar with the anode will be 
deeply stained with the methyl-blue, the pigment having penetrated the 
hair-follicles, sweat-glands, and cutaneous crevices, producing a discolora- 
tion which cannot be washed away, and will remain for several days ; while 
the hand which was immersed in the jar containing the cathode can be 
readily cleaned by a simple washing. 

When this peculiar power or expression of electric force possessed by 
the direct current is applied to therapeutics, it is used to convey medicinal 
substances in solution which have been placed in contact with the positive 
electrode, — anode, — or with the negative electrode,— cathode,— into the 



CATAPHORESIS. 195 

tissues of the body or through thern, with the object of securing the local 
effect of such remedial agents. 

In dental surgery this may be applied to decolorizing or bleaching 
devitalized teeth, in sterilizing the dentin, or producing local anaesthesia 
in sensitive dentin. 

The power of the galvanic current, however, is not limited to the con- 
veying of medicinal substances in solution, but it may be employed to 
transfer substances already in the tissues, whether of normal or abnormal 
composition, from one part of the body to another, or from the deeper 
tissues within any part of the body to the surface, with the object of en- 
tirely removing such substances. 

The fluids of the body and many medicinal substances, when subjected 
to the electrolytic action of the direct current, flow in a constant direction 
from the positive to the negative pole, but certain other chemical sub- 
stances, which may be dissolved or held in suspension in the fluids of the 
body, applied to the surface, have been found to travel in an opposite 
direction, — viz., from the negative to the positive pole. 

At the present time the subject of cataphoresis is still more or less in 
the experimental stage, and the electric affinity or direction in which the 
various medicinal agents will travel when subjected to the galvanic current 
has only been determined for a few of them, so that it becomes necessary 
to establish this fact by experiment for each new remedy used before 
attempting to apply it cataphorically. 

The phenomena which are included under the term cataphoresis, or 
electric osmosis, ' ' must be regarded as the result of several causes oper- 
ating at the same time and more or less interdependent, since certain of 
these phenomena are electrolytic, some mechanical, and others chemical." * 

Most physicists explain or base their explanation of the phenomena of 
cataphoresis upon the law first discovered by Thales about 600 B.C., — 
viz., that amber when briskly rubbed attracted light bodies like chaff 
and bits of paper. This law is now expressed as follows : u When a dif- 
ference of potential is established by a direct current of electricity sent 
through a collection of molecules, each atom or molecule of any substance 
that is free to move deports itself according as the electric charge which it 
receives is positive or negative. Those ions, atoms, or molecules with a 
negative charge will move towards the anode, and those with a positive 
charge towards the cathode." f , 

The direction, therefore, according to this law, in which a remedy in 
solution will be conveyed by the application of the galvanic current, 
whether from the positive to the negative pole or the reverse, will depend 
upon the electric affinity of the disassociated ions, or, in other words, upon 
the initial charge which they have received. 

There is a question, however, in the minds of some physicists as to 
whether this is not the real explanation of cataphoric action, rather than 
that the current by its electromotive force or driving power forces the 

* Lectures, National School of Electricity. 
t Ibid. 



196 OPERATIVE DENTISTRY. 

remedy in solution into the tissues, as was generally supposed a short 
time ago. 

Among the chemical substances which have been proved upon good 
authority to be conveyed into the tissues when applied by the anodal 
electrode of the galvanic current are cocaine hydroehlorate, aconitine, 
tincture of aconite, helleborine, mercuric chloride, mercuric succimide, 
lithium chloride, strychnia nitrate, strychnia sulphate, menthol, and thy- 
mol, while sulphur, eosine, potassium iodide, and the bromide salts are 
conveyed from the cathodal electrode. 

Electrolysis. — Many chemic substances and compounds are decom- 
posed by the action of an electric current, while the liberated elements 
show different attractions, some of them travelling to the positive pole, 
others to the negative. 

This phenomenon of dissolution is denominated electrolysis, the com- 
pound decomposed or acted upon an electrolyte, and the products of elec- 
trolysis are termed ions. The elements thus liberated are attracted to one or 
the other of the poles ; those which are attracted to the positive pole are 
called anions ; those attracted to the negative pole are designated cations. 

As an illustration of the electrolytic decomposition of chemic substances 
the familiar experiment of decomposing water by the action of an electric 
current may be cited. In this case the elements composing the water are dis- 
associated, and the ions immediately seek their electric attraction, the hydro- 
gen—which is a cation or electropositive element — collecting in the form 
of bubbles at the negative or cathodal electrode, and the oxygen — an anion 
or electronegative element — gathering at the positive or anodal electrode. 

In carrying this phenomenon a step farther to more complex chemic 
substances, it is found that " by passing a galvanic current from a primary 
battery or from a dynamo, through a liquid containing a metallic salt in 
solution, such as nitrate of silver, the metallic salt is decomposed, the 
metal being deposited upon the cathodal electrode, while the nitrogen 
enters into other compounds, as with oxygen, forming nitric acid, which 
accumulates at the anodal electrode." * 

Decompositions of the same general character take place in all com- 
pound solutions, regardless of their degree of density, whenever they are 
made a part of the circuit of a galvanic current. The chemic constitution 
of such solution immediately begins to undergo electrolytic dissolution ; 
the acids, oxygen, chlorine, and the electronegative elements collect 
about the positive electrode, while the alkalies, hydrogen, and the electro- 
positive elements collect about the negative electrode. 

' • If these termiuals or poles in contact with the solution are suitably 
devised electrodes, and the solution is some one of the tissues of the human 
body, — for such tissues, though differing in density, are bathed in liquids 
and permeated by them, — physical effects similar to those just described 
follow the passage of the current, the result depending upon the nature 
and composition of the tissues involved, the strength of the current, and 
the length of time it is permitted to flow." f 

* Lectures, National School of Electricity. f Ibid. 



CATAPHORESIS. 197 

The character of the changes which take place in the electrolytes — 
fluids or animal tissues — at distant points from the electrodes in the track 
of the current is not known, while "it is difficult to account for the phe- 
nomena of decomposition which takes place at the electrodes without as- 
suming that some kind of rearrangement of the molecules composing the 
electrolytes occurs along the entire track of the current." * 

Anodal Electrolysis. — This term is used to designate those phenom- 
ena which take place at the positive pole, or anode, as a result of the appli- 
cation of a galvanic current to or its passage through the tissues of the 
living human body. 

Its action may be experimentally shown by taking a piece of fresh, lean 
meat and passing a needle into it which is connected with the positive 
pole or anode of a galvanic current having a strength of from five to ten 
milliamperes, the cathode being placed upon the opposite side. After the 
current has been allowed to pass for a few minutes, it will be noticed that 
at the point of insertion of the needle the meat has become dry, white, 
and shrunken. The extent and depth to which this effect may be carried 
into the tissue will depend upon the strength of the current, the length of time 
it is employed, and its density, the latter being determined by the size of 
the needle or anodal electrode. This effect in a measure is the result of 
the coagulation of the albuminoid substances contained in the tissues from 
the action of the acids collected at the anode, and partly to cataphoresis, 
or the electric affinity of ions possessing an electropositive charge, which 
directs them to the cathodal electrode. 

If the needle or anode is made of a material that is not readily oxidized 
— like gold or platinum — and is not materially acted upon by acids or 
chlorine, no change other than that just mentioned is observable in the 
tissues ; but if the needle employed is of iron, steel, or copper, salts are 
formed, and the tissues in its immediate vicinity are stained by a deposit 
of the oxide or oxychloride of the metal used. 

The drying of the tissues in the vicinity of the anode is due to 
the cataphoric effect of the current which carries the fluids towards 
the cathode, or to the migration of electropositive ions which seek their 
affinity at the negative pole. This phenomenon may be illustrated by 
passing a galvanic current through a piece of wet clay. In a few 
minutes the surface of the clay in the vicinity of the anode will begin 
to show signs of drying and hardening, while at the cathode the mois- 
ture will collect in increasing quantity and softening of the surface take 
place. 

It may be stated briefly, therefore, that the effeat of anodal electrolysis 
upon animal tissue is destructive, but that this destructive action may 
be employed to advantage in the treatment of various pathologic con- 
ditions where this destructive effect, if judiciously used, would retard or 
entirely arrest the progress of the diseased condition. 

The phenomena of anodal electrolysis which takes place in animal 
tissues are : 

* Lectures, National School of Electricity. 



198 OPERATIVE DENTISTRY. 

1. The accumulation of oxygen, chlorine, and acids in the vicinity of the 
electrode. 

2. The tissues in contact with and immediately surrounding the elec- 
trode, as the result of the accumulation of the above destructive anions, 
suffer more or less disintegration by the disturbance of their molecular 
composition, which later causes structural changes and arrest of function. 

3. The acids formed at the anode, reacting upon the albuminoid sub- 
stances and other organic elements contained in the tissues, produce astrin- 
gent, styptic, bleaching, and coagulating effects upon those parts with which 
they come in contact. 

4. When the electrode is made of some material which is readily 
oxidized, or has a strong affinity for the acids which collect about it, 
secondary chemical compounds are formed, like oxide or chloride of iron, of 
copper, or of zinc, as the case may be, which may j)ossess therapeutic 
value or may produce indelible staining of the tissues. 

The therapeutic employment of the secondary products formed at the 
anode or cathode is termed metallic electrolysis, but this function is almost 
exclusively confined to the anode. 

Anodal electrolysis has a wide range of therapeutic application in both 
general and special surgery. In dental surgery and stomatology it may be 
applied to the removal of cysts and new growths upon the tongue or oral 
mucous membrane ; to hemorrhagic conditions of this membrane, and in 
hemorrhage after extraction ; to phagedenic ulcers, follicular diseases, and 
inflammatory conditions due to low forms of bacterial life ; to the local 
treatment of pyorrhoea alveolaris ; to the production of aseptic conditions 
in devitalized and suppurating teeth, and to decolorizing or bleaching de- 
vitalized teeth. 

Cathodal Electrolysis. — This term is used to designate those phe- 
nomena which take place at the negative pole or cathode as a result of the 
application of a galvanic current to the tissues of the body. When such 
a current is passed through the compound solutions which compose a 
larger part of every animal tissue, the constituents of the tissues in the 
immediate vicinity of the cathode are decomposed, the hydrogen and the 
alkali ions gathering about the cathodal electrode. The alkalies which are 
thus collected are principally soda and x^otassa. 

Inasmuch as these substances do not possess chemic affinity for the metals 
generally used for electrodes, with perhaps the exception of aluminum, 
which is corroded by the alkali ions, forming aluininates of soda and 
potassa, but which do not seem to possess any therapeutic value when 
locally applied, it onlybecornes necessary to consider the action and dis- 
position of the hydrogen and the alkalies. If a piece of fresh meat or egg 
albumin be subjected to the action of a galvanic current, it will be ob- 
served that the hydrogen gas which collects at the cathode will bubble up 
and escape, or be detained in the meshes of the tissues, while the soda and 
potassa will unite with the albuminoids of the tissues immediately sur- 
rounding the cathodal electrode, causing softening of these tissues, and if 
continued for a sufficient period of time in the living body, disintegration, 
loss of vitality, structural changes, and liquefaction will take place. 



CATAPHORESIS. 199 

The phenomena presented by cathodal electrolysis, therefore, are : 

1. The accumulation of hydrogen and alkalies in the vicinity of the 
electrode. 

2. The presence of hydrogen gas in the meshes of the tissues or its escape, 
and the union of the alkalies with the albuminoids of the tissues. 

3. The softening of the tissues in the neighborhood of the electrode and 
their final liquefaction. 

From the foregoing statements it will be observed that the phenomena 
of cathodal electrolysis are also destructive in their nature to the living- 
tissues when much prolonged, and yet these phenomena when skilfully 
applied to certain pathologic conditions are capable of being rendered 
most beneficial. 

Cathodal electrolysis has its greatest usefulness in the softening and re- 
laxation of cicatricial tissue, in the reduction of hyperplasias and other 
inflammatory growths, in the removal of fungous growths, and in the 
treatment of bony and cartilaginous enlargements, especially of the nasal 
passages, the alveolar processes, and the palate. 

Ordinarily the electromotive force required for electrolytic work will 
not exceed twenty volts, but the resistance of the tissues is so variable 
that a current of the strength of ten to fifteen milliamperes is not infre- 
quently employed, making a greater electromotive force necessary for the 
most efficient work. 

THE GENERAL PRINCIPLES OR LAWS WHICH GOVERN THE GENERATION 
AND TRANSMISSION OF ELECTRICITY. 

Generation. — Electricity may be generated, first, by friction, when it 
is termed frictional or static electricity ; secondly, by chemic action, when it is 
termed chemic electricity ; thirdly, by induction, when it is known as induced 
electricity. 

The first is a form of electricity used largely in medicinal practice, and 
is generated by a machine in which a glass disk is made to revolve rapidly 
while in contact with specially prepared rubbers, the electricity being col- 
lected and stored by apparatus adapted to the purpose. 

The second or chemic electricity is generated by primary or galvanic 
batteries. 

Primary batteries, of which there are a number of different forms, are 
composed of two plates of different metals, —the elements, — as copper and 
zinc, or of one metal and a non-metallic substance, as carbon, which are 
placed in a jar containing a liquid — the electrolyte — composed of a solution 
of sulphuric acid or of ammonium chloride, zinc chloride, or other suitable 
solution, the two plates being connected together outside of the liquid, 
when, by the chemic action taking place between the elements and the 
electrolyte, a current of electricity is generated. This constitutes a cell 
of a primary or galvanic battery. A battery may be composed of a single 
cell or any number of cells joined together in series by connecting with 
copper wire the negative pole of one cell to the positive pole of the next, 
and so on until the series is completed. The wire or cord attached to the 
copper element of the first cell would be the positive pole, while that 



200 OPERATIVE DENTISTRY. 

attached to the zinc element of the last cell would be the negative pole. 
The current travels in the outside circuit from the positive to the negative 
pole. The poles are determined by the direction in which the current 
flows ; the plate from which the electric current flows outside the liquid is 
termed the positive pole, while the plate to which the current returns out- 
side the liquid is denominated the negative pole. In a cell composed of 
copper and zinc elements, with dilute sulphuric acid as the electrolyte, the 
zinc is most violently acted upon, and the electric current generated flows 
from the zinc or positive element through the liquid to the copper or negative 
element, and from that through the external conductors or wires back to the 
zinc element, thus completing a circuit. That portion of the zinc plate which 
is immersed in the electrolyte is positive to that part of the copper jflate 
which is likewise immersed, but the portion of the copper plate above the 
liquid is positive, while the same portion of the zinc plate is negative. 
To indicate these conditions the signs plus (+) and minus ( — ) are used. 

Primary batteries are divided into two classes, — viz., open circuit and 
closed circuit batteries. The open circuit battery is one which works best 
when not in constant use, and is usually employed for call-bells and signal 
circuits generally. The " Leclanche" is the best of this class of batteries. 
In this the elements used are zinc and carbon ; the electrolyte is a solution 
of ammonium chloride ; the carbon, being placed in a porous jar and sur- 
rounded by powdered manganese dioxide, is suspended in the liquid in 
the centre of the battery jar, and the zinc element is suspended at one side. 
This form of battery, if made to work continuously, soon runs down, and 
must be given a period of rest before it can be used again. When only 
brought into action for brief periods at a time it works most satisfactorily. 
The electromotive force of such a cell is about 1.47 volts. 

The class of batteries known as closed circuit batteries comprise those 
varieties which work best when in constant service. The "gravity" 
battery, which is a modification of the "DanielL" is the best of this class. 

The gravity battery is formed by placing the copper element in the 
bottom of the battery jar and suspending the zinc element from the top ; 
these are cast in the form of a wheel or ' ' crowfoot. ' ' A cupric sulphate 
solution is then poured over the copper element, and a quantity of cupric 
sulphate crystals added. Upon this solution is carefully poured a solution 
of zinc sulphate. The specific gravity of the two solutions is so different 
that they do not readily mix ; the cupric sulphate solution, being the 
heavier, remains at the bottom of the jar. The zinc sulphate solution takes 
the place of the sulphuric acid in the Daniell's cell, and although it does 
not give quite so high a voltage, the action of the cell is more even 
and constant. The potential of such a cell is from 1 to 1.14 volts. 

The dry cell battery is made either upon the principle of Zamboni's dry 
voltaic pile, or some such substance as sand, sawdust, or paper, moistened 
with acidulated water, separates the elements in each cell. 

Secondary or storage batteries are composed of two or more plates of the 
same metal, — generally lead, — which are placed in a solution which, under 
ordinary circumstances, does not attack the metal, — usually dilute sulphuric 
acid, — and consequently no electricity is generated. But if a current of 



CATAPHORESIS. 201 

electricity, generated from some outside source, like a dynamo furnishing 
a one-hundred-and- ten- volt electric lighting current, is allowed to pass 
through the battery, a chemic action is set up in the solution termed 
charging, which decomposes it and causes plumbic dioxide (Pb0 2 ) to be de- 
posited upon one plate and metallic plumbum (Pb) in a spongy form upon 
the other. This forms a battery of two different elements, — viz., PbO, 
and Pb immersed in an electrolyte, hydric sulphate (H,S0 4 ) — sulphuric 
acid — of full strength and specific gravity, which is capable of acting 
upon them. 

The lead plates which form the element must be so constructed as to 
present a large surface upon which the chemic action may take place, as 
the amount of energy which can be stored in a cell depends upon the 
capability of the plates to appropriate the results of the chemic action. 

If the poles of the battery are now brought together and the circuit 
closed, a current of electricity will be immediately generated. In the 
chemic action which takes place during the discharge of the battery, one 
atom of oxygen (O) contained in each molecule of the Pb0 2 will pass to 
the opposite plate, joining with the Pb and forming plumbic oxide (PbO). 
This process continues as long as any molecule of Pb0 2 remains upon the 
surface of the plate to give up its oxygen. When no more oxygen is 
liberated both plates become alike (PbO) over the entire surface. 

The sulphur radical in the electrolyte (H,SOJ enters into combination 
with the active material on both plates, forming plumbic sulphate (Pb,S0 4 ), 
the specific gravity of the electrolyte being correspondingly reduced. 
When all of the active material has been changed in this manner the cell 
is said to be discharged, for an ecpiilibrium has been created between the 
two plates and the electromotive force is reduced to zero, and so remains 
until it is again charged by an electric current from the outside. Secondary 
batteries discharge their electric current in an opposite direction from that 
in which they were charged. Like primary batteries, the potential or 
electromotive force does not depend so much upon the size of the elements 
as upon the materials composing them and the nature of the electrolyte ; 
but the amount of the electric energy furnished by any cell will depend 
upon the area of the surfaces of the elements exposed to the action of the 
electrolyte. 

The electromotive force of the charging current should be about twice 
as high as that of the cells to be charged. On the other hand, the amount 
of current charged per hour should not exceed what is called the normal 
charging rate, and which differs according to the size of the cells. The 
normal rate of charge for small storage batteries is about ten hours, and 
if a cell has a capacity of fifty ampere hours, not more than five amperes 
should be charged, and for a cell of one hundred ampere hours, not more 
than ten amperes should be charged. 

The rate of charge should be preferably kept at normal or under, as 
continuous charging at a higher rate than normal would injure the 
plates. 

Storage batteries, however, have never come into general use for medi- 
cal or dental purposes, and although they have been used to some extent 



202 OPERATIVE DENTISTRY. 

for heating cauteries and lighting exploring lamps, they are by no means 
a convenient or economical method of obtaining an electric current. 

Induced Electricity. — This form of electric current is produced by 
dynamo-electric machines, and is the common current now used so exten- 
sively for illuminating and power purposes. There are two general classes 
of dynamo-electric machines ; one class produces an alternating current, 
and the other a continuous current. 

The modern Edison dynamo-electric machine so generally used all over 
the world for lighting houses and shops and running small motors 
delivers a continuous current. This current is often used for thera- 
peutic purposes by the physician, surgeon, and dentist. The current 
delivered by such a dynamo differs from that delivered from the primary 
battery in that it has a slight but uniform variation in strength. The 
strength of the current coming from a primary battery may be represented 
by a straight line, while that from the dynamo would be by comparison 
represented by a line waving slightly but uniformly. It has not been 
definitely determined whether this difference in the current has any effect 
upon the constituents of the body, but so far as known they seem to act 
alike. 

The most convenient dynamo current for therapeutic uses is the Edison 
direct current of one hundred and ten volts. The pressure of this current 
varies from one hundred to one hundred and twenty-five volts, according 
to the position on the mains. The electromotive force can be reduced to 
any degree necessary to conform with the requirements of the physician, 
the surgeon, or the dentist by lamps or other resistances and shunts. By 
employing this form of current much of the annoyance attending the 
operation of primary batteries is obviated, and with the now quite com- 
mon practice of placing the mains in underground conduits, the dangers 
from lightning or crossing with wires of dangerous potential is reduced 
almost to nil. 

Transmission. — Electric currents are transmitted, conveyed, or con- 
ducted by various substances, like metals, charcoal, graphite, fluids, ani- 
mal tissues, etc. Any substance which is capable of conveying electricity 
is termed a conductor, and those substances which do not convey it are 
termed non-conductors ; dry air, glass, vulcanized rubber, porcelain, etc., 
belong to the latter classification. 

In substances which are perfect conductors, like silver and copper, 
electricity moves with absolute freedom under any electromotive force, no 
matter how small. Copper wire is generally used as a means of conduct- 
ing electric currents. 

The conducting power of pure silver is 100, that of copper 97. In 
substances which are perfect non-conductors, electricity will not move 
under any electromotive force, no matter how great. In substances which 
are imperfect or partial conductors, electricity moves only upon the exhi- 
bition of great electromotive force, the amount of electromotive force 
required varying according to the ability of the substance to convey an 
electric current. 

The transmission of electric currents is through metallic conductors, 



CATAPHORESIS. 203 

copper wire being chosen for economic reasons. The resistance of these 
conductors is varied by the character of the metal, the cross-section (size), 
and the distance to which the current is conveyed. 

The percentage of conducting power possessed by the various metals 
and alloys employed in electric work is as follows : Silver, 100 ; copper, 
97 ; gold, 75 ; aluminum, 54 ; zinc, 28 ; platinum, 17 ; wrought iron, 16 ; 
nickel, 12 ; tin, 12 ; lead, 8 ; mercury, 1.6 : cast iron, 3 ; platinum silver 
made of two parts platinum and one part silver, 6.1 ; German silver made 
of five and one-half parts copper, two parts zinc, and two and one-half 
parts nickel, 3. 5 ; German silver made of six parts copper, two and one- 
half parts zinc, and one and one-half parts nickel, 5 ; German silver made 
of five parts copper, three and one-half parts zinc, and one and one- 
quarter parts nickel, 7.5. 

Units of Measurement. — The electromotive force, or electric pressure 
furnished by the cell or the dynamo, is the force which moves the current 
against the resistance of imperfectly conducting substances, and is termed 
voltage. 

The active energy of electricity lies in a property designated as its cur- 
rent strength, and is termed its amperage. 

The unit of quantity is the coulomb. 

The unit of pressure is the volt 

The unit of strength is the ampere. 

The unit of resistance is the ohm. 

The unit of power is the watt. 

A coulomb represents the quantity of electricity that passes during one 
second through a conductor having a resistance of one ohm, with one volt 
of electromotive force. 

A volt represents the electromotive force (E. M. F.) which is required 
to move one ampere of current through oue ohm of resistance. This force 
may be represented, for example, by the pressure necessary to move a cer- 
tain number of gallons of water per minute through a pipe of given size ; 
reduce the size of the pipe and the resistance becomes greater, thus call- 
ing for a greater degree of pressure to accomplish the task. 

An ampere represents the volume of an electric current carrying one 
coulomb per second ; hence it is the measure of the rate of flow of an 
electric current, and, in connection with the voltage, measures the energy of 
the current. 

The measurement of the ampere of current is based upon the electro- 
chemical effects of currents, and is defined as that much current which 
will deposit silver at the rate of 0.0001118 grammes per second from a 
standard solution of silver nitrate in water, or which will decompose 
0.00326 milligramme of water in one second. 

An ohm of resistance is defined as equal to the resistance of a column 
of pure mercury which is 106.3 centimetres long, and has a uniform cross- 
section which contains 14.4521 grammes of mercury, the temperature being 
that of melting ice. This gives the column the uniform cross-section of 
one square millimetre. The ohm is that degree of resistance which will 
allow one ampere of current to pass under a pressure of one volt. 



204 OPERATIVE DENTISTRY. 

According to Ohm's law, when a current of electricity flows through a 

wire, under the pressure from a battery or other sources of electricity, 

the effective strength of current which flows in the circuit is equal to the pressure 

E 
divided by the resistance of the circuit. It is often written thus : C = -^, when 

0, E, and E stand for current pressure (electromotive force) and resistance, 
and may be read C equals E divided by E. It is evident, also, from the 
relation as written above, that E equal C times E, and E equals E divided 
by C. By this law if any two out of the three fundamental electric quan- 
tities which exist in a circuit are known, the third can at once be calcu- 
lated. Thus, if a sixteen-candle-power incandescent lamp is known to 
take one-half an ampere when attached to a circuit which furnishes a 
current at a pressure of one hundred and ten volts, the resistance of the 
lamp when in operation may be calculated at once to be one hundred and 
ten divided by one-half, which gives the resistance of two hundred and 
twenty ohms. Or if two cells of a battery, each furnishing a pressure of 
1.1 volts, and each having an internal resistance of three ohms, be con- 
nected with an external circuit of 2.8 ohms' resistance, then the total resist- 
ance in the circuit is 8.8 ohms, and the pressure which acts to pass the 
current through the circuit is 2.2 volts. The current flowing under these 
circumstances is therefore one-quarter ampere (C = BE or \ = 2.2/8.8). 

A watt is the amount of power developed by a current of one ampere, 
having an electromotive force of one volt. It is the unit of electric work, 
and represents the power exerted by one ampere of current at one volt of 
pressure. 

These propositions may be written thus : 

Amperes = volts -s- ohms. 
Ohms = volts ■*- amperes. 
Volts = amperes X ohms. 
Watts = volts X amperes. 

RHEOSTATS ; CURRENT SELECTORS ; CURRENT CONTROLLERS. 

Rheostats.— Electric currents furnished by the various means already 
mentioned — viz., primary batteries, secondary batteries, and dynamos— need 
to be modified in strength in order to adapt them to the requirements of 
therapeutics. This may be accomplished by adding resistance to the ex- 
ternal current, or by diverting a portion only of the available current into 
the circuit with the patient. 

The substances which are introduced for the purpose of reducing the 
energy of the current by the interposition of increased resistance are 
selected because of their great resistance to the passage of electric cur- 
rents. These substances are water, carbon, graphite, aud coils of German 
silver wire. 

Eheostats when constructed for therapeutic work have a mechanical 
device for increasing and decreasing, at the will of the operator, the 
amount of resisting substance in the circuit. 

"Water Rheostats. — Water rheostats vary in resisting capacity accord- 
ing to the quantity and purity of the fluid admitted into the circuit. Dis- 



CATAPHORESIS. 



205 



tilled water only should be used for such purpose. The current in passing 
through this resistance heats the water and decomposes or electrolyzes it. 
If the water is impure, deposits occur or the metal plates may be corroded, 
thus impairing the usefulness of the instrument. The chief objection to 
this form of rheostat is the fact that there is no simple or elementary 
means of measuring with accuracy such form of resistance. 

In the water rheostat one pole is attached to two metal plates separated 
by about three-fourths of an inch and placed in the bottom of the glass 
receptacle containing the water. The other pole is attached to a sliding 
rod worked with a ratchet, the rod having attached to its lower end an 
angular plate of metal with the apex pointing downward, — both poles 
should be made of platinum, — which, as it is lowered into the water, 
increases the surface of this pole in contact with the water, and thus de- 
creases the resistance. The current passes from the battery — or a suitable 
lamp resistance or shunt when the street main is used — through the water 
and the patient in series. The current is controlled by raising or lower- 
ing the pole having the angular plate of metal attached to its lower end. 

Carbon and Graphite Rheostats. — This form of rheostat is usually 
constructed in the shape of a broken ring, one pole being attached to one 
end of the ring, and the other pole to the index which travels over the 
circular disk (Fig. 316). These serve fairly well for modifying the cur- 

Fig. 316. 




Jewell graphite rheostat. 

rents from portable and stationary batteries, and also from dynamos when 
the amount of current used is small. They have the advantage of fur- 
nishing a high resistance in a very small compass, but they also have a 
disadvantage in that they cannot be graduated, since their resistance is 
variable even in instruments of the same size and shape. 

German Silver Wire Rheostats. — German silver wire rheostats 
when well made are the most reliable and constant, and have this advan- 
tage over all other forms, that the resistance which they offer can be accu- 
rately measured. In this form of rheostat the degree of resistance is 
regulated by the length and the diameter of the wire, the cross-section 
being reduced to the smallest size which will conduct the current without 
overheating ; it is therefore graded with especial reference to the amper- 



206 OPERATIVE DENTISTRY. 

age of the current it is expected to convey. In the construction of this 
form of rheostat two general methods are followed : one is to arrange the 
wire in unbroken coils between a certain number of contact points, dis- 
posed at equal distances from each other around a broken ring, one pole 
attached to one end of the broken ring, as in the graphite rheostat, and the 
other pole to the index which travels over the contact point. The other 
method is to wind the wire upon spools of fibre, one arranged as a per- 
manent resistance, the other as a shunt resistance. The coil of the shunt 
resistance is wound in notches of a small fraction of an inch, and a con- 
tact-shoe is made to move from one end of the coil to the other, and in 
doing so touches several hundred turns of the wire, thus giving as many 
different gradations of current flow. 

In the use of high voltage currents, such as the one-hundred-and-ten- 
volt circuit, it may be switched through the coils of such a rheostat and 
reduced to any degree required. 

A current selector is a mechanical device for throwing a greater or less 
number of cells of a primary or secondary battery into the circuit. The 
amount of current can thus be made to vary as the exigencies of the case 
demand, while the electromotive force is gradually increased and decreased 
at the will of the operator. 

A current selector or switch of this character does not, however, do 
away with the necessity of a rheostat, especially if it is constructed to in- 
crease the number of cells thrown into the circuit by groups rather than 
singly. 

Dynamo Current Controllers. — These are resistances especially 
adapted to the dynamo current, either to be put in series with the patient 
or so constructed as to form a shunt circuit with the patient's circuit. In 
the former case the current is modified by a rheostat capable of increasing 
and decreasing the resistances, while in the latter the device is such as to 
admit a greater or less flow of current into the shunt circuit. The princi- 
pal difference between these methods of controlling the dynamo current 
is that in the former the electromotive force remains the same regardless 
of the amount of current the patient is receiving, while in the latter this 
electromotive force varies with the current received. 

These instruments can be so controlled that the graduation will be exact. 

Milliamperemeters. — Exact work in electrotherapeutics cannot be 
accomplished when using the direct current without the means of accu- 
rately measuring that current. 

The milliamperemeter offers the means of measuring the strength 
of the current being used, and this is of first importance in cataphoric 
work, as it enables the operator to measure the resistance of the tissues in- 
volved in the circuit, and offers a sure means of detecting any leakage of 
the current, which is also important, for if it is not discovered, it prolongs 
the time necessary to produce the desired result or cause it to end in com- 
plete failure. Currents used upon the body for therapeutic purposes never 
exceed one-half an ampei'e, or five hundred milliamperes, and for nearly 
all cataphoric work much less thau this, from five to twenty milliamperes 
being about the limits of the customary range. 



CATAPHORESIS. 



207 



Fig. 317 




Weston's dead-beat milliam- 
peremeter. 



Five niilliamperes of current for dental cataplioresis is often more than 
can be used. A current strength of from two-tenths to two milliamperes 
is usually all that can be borne without pro- 
ducing pain. 

There are two forms of milliamperemeters in 
use by physicians and dentists. In one the needle 
is magnetic and arranged to freely turn upon a 
pivot, and is easily influenced by outside magnetic 
forces. The needle is deflected away from the 
earth's magnetic meridian by the electric current 
which traverses a coil of wire which is parallel 
with the magnet before the current passes. In 
the other the construction is such that the indi- 
cator comes instantly at rest, and has no period 
of oscillation before the measurement can be read, 
— in other words, it is what is termed "dead-beat." (Fig. 317 shows such 
an instrument.) These instruments are made with a double scale, one for 
strong and the other for weak currents, the scale for the weaker current 
being divided into twentieths of a milliampere. 

Conducting Cords and Tips. — The conducting cords are made of 
bunches of fine copper wire covered with cotton or silk, and should be 
pliable as well as strong and durable. If the cords are not made of good 
material, the strands or threads are liable to be broken with use, and the 
current thus be rendered fitful or interrupted by such defects. 

The tips or terminals are metal devices placed at either end of the con- 
ducting cords for attaching them to the binding posts and the electrodes. 

Electrodes. — These of necessity are made of various materials and 
of many sizes and shapes to meet the demands of special forms of treat- 
ment. The practical medical and surgical electrotherapeutist will need 
an entirely different line of electrodes from those required by the dental 
surgeon. Fig. 318 shows a selection of electrodes employed by the dental 
surgeon. 

ELECTROCOCAINE ANAESTHESIA. 

As a means of obtunding hypersensitive dentin, anaesthetizing the den- 
tal pulp, and producing local anaesthesia for tooth extraction, the cata- 
phoric or electrolytic action of the direct electric current in carrying 
cocaine into the dental tissues and thus paralyzing the function of sensa- 
tion bids fair to become the most important means which has ever been 
placed in the hands of the dentist for relieving the pain of dental opera- 
tions. Many successes and also many failures have been reported in the 
use of cataphoresis. The failures have been the result, no doubt, of those 
conditions which always surround any new method of treatment, espe- 
cially if it introduces remedies or forces the action of which are more or 
less imperfectly understood, as was the case with nitrous oxide, ether, and 
chloroform. But in time these difficulties will be eliminated by research 
and experimentation, and the methods of treatment so perfected that fail- 
ures will become either a matter of an individual idiosyncrasy of the 



208 



OPERATIVE DENTISTRY. 



patient or of a lack of ability upon the part of the operator to manipu- 
late the apparatus. 

The solutions of cocaine which are used in cataphoresis vary in strength 
from ten to forty per cent. These solutions may be made from either the 

Fig. 318. 






/■ 





Cataphoric electrodes. 



hydrochlorate or the citrate, dissolved in distilled water, glycerol, guaiacol, 
or guaiacol and ether. Morton recommends making fresh solutions for 
each case, because of the fact that cocaine solutions deteriorate and lose 
their anaesthetic property in a large measure in a few days. 



CATAPHORESIS. 



209 



Fig. 319. 




Apparatus. — The apparatus necessary for producing electrococaiue 
anaesthesia are a suitable primary galvauic battery ; preferably a dry-cell 
chloride of silver, or a dry-cell Leclanche battery, having an electro- 
motive force of from ten to thirty-five volts ; a reliable rheostat or con- 
troller so arranged that the current 
may be increased or diminished by 
slow gradations at the will of the oper- 
ator ; a milliamperemeter graduated 
to register the twentieth part of a 
milliampere ; conducting cords and 
electrodes. 

The secondary or storage battery 
is sometimes employed for producing 
cataphoresis. When this form of bat- 
tery is used the plates should be 
small, — three by three inches. The 
potential of a cell of this size will 
be about two volts, and the normal 
strength of current at eight hours' 
discharge is five-eighths of an ampere. 

The Edison one-hundred-and- ten- 
volt street current may also be em- 
ployed by suitably reducing the 
strength of the current. The objec- 
tions which have been raised to the 
use of this current are the dangers 

from severe shock, if by chance the apparatus should be defective, or 
lightning should strike the supply wire, or it should become crossed with 
one carrying a current of much higher potential. These dangers may be 
guarded against by placing the mains underground, as is now being done 
in all of our large cities, and by inserting a suitable fusible -wire connection 
in the apparatus that will not carry a current of greater strength than 
one-half an ampere. 

In the arrangement of the apparatus for cataphoric work, the battery, 
or other source of current, the rheostat, the milliamperemeter and the 
patient are in series (Fig. 320). The direction of the current being from 
the battery to the rheostat, from the rheostat to the milliamperemeter, 
from the milliamperemeter to the patient, from the patient back through 
the rheostat to the battery, thus making the circuit complete. 

The resistance encountered in the flow of the current are found in the 
conducting wires, the rheostat, and the tissues of the patient ; the skin 
and the dentin being more highly resistant than the other tissues through 
which the current must pass in treating hypersensitive dentin. The result 
of resistance to the flow of an electric current is the production of heat, 
the amount of heat produced being governed by the degree of the resist - 
tance, and the size and character of the conductor. 

Dentin is exceedingly resistant to the passage of a current of electricity, 
consequently heat is liable to be produced if the pressure of the current is 

14 



Cataphoric outfit without milliamperemeter. 



210 



OPERATIVE DENTISTRY. 



too great, and pain would be the result. The teeth are very sensitive to 
an electric current, and respond vigorously to any sudden change in the 
pressure or strength of current- flow or amperage. There is, however, a 
considerable variation between individuals and between different teeth in 
the same individual as to the amount of current that can be used upon 
the teeth without causing pain. With some individuals the limit is 



Fig. 320. 




yj fe fct.l«* Batto/ 



I rT" 


1J*-! 


n ft* 


>rr 


vrP* 


r* 


v w 


Tt fP 1 






Sfy 




B,, 




T»y 






Biy 




Dry 


cat 




c.\l 




C*U, 






CtU 




au 



reached with a pressure of four or five volts and one-tenth of a milli- 
ampere of current. Under such circumstances it becomes necessary to 
increase the pressure very slowly until the cocaine paralyzes somewhat the 
function of sensation in the dentin. While in others the pain limit may 
nnt, be attained until the pressure reaches fifteen to twenty volts, with an 



CATAPHORESIS. 211 

amperage of from three-tenths to four-tenths of a milliampere. The 
anterior teeth seem to-be the most susceptible to the galvanic current. 
Teeth having acutely inflamed pulps are also exceedingly sensitive to the 
current, even at very low initial voltage. 

Another factor in this connection which must be taken into considera- 
tion is the nervous irritability of the patient, which when highly exalted 
may render them peculiarly susceptible to the irritation of an electric 
current. 

Resistance of Tissues. — According to Dr. W. A. Price,* the average 
resistance of a patient is about twenty-five thousand ohms from the cavity 
to the hand holding the negative electrode or cathode. This was com- 
puted from twenty-five cases, varying all the way from ten thousand to 
seventy-eight thousand ohms and higher. The difference of resistance from 
the band to the tooth and from the cheek to the tooth he found to be from 
three thousand to five thousand ohms. In one case, in which the resistance 
was measured with the cavity barely moist, it gave a resistance of forty- 
seven thousand seven hundred ohms. On applying a forty per cent, solu- 
tion of cocaine in water to the cavity, the resistance was reduced to 
twenty-eight thousand five hundred ohms, and upon transferring the 
cathode to the cheek it was further reduced to twenty-three thousand eight 
hundred ohms. 

The greater portion of the resistance is, therefore, according to the 
above statements, in the tooth. 

Dr. Price further states that the average resistance from the hand to 
the tongue with small electrodes is about nine thousand ohms, varying 
from seven thousand to twelve thousand ; and from the cheek to the tongue 
about five thousand ohms, varying from three thousand to seven thousand. 
This places the greater part of the resistance of the tissues of the patient 
in the dentin of the tooth, which varies all the way from ten thousand to 
seventy thousand ohms, with an average of about twenty thousand. 

Sections of dentin in the fresh state tested out of the mouth in an 
almost dry condition, and also when saturated with various solutions, gave 
a wide range of resistance. As an illustration, a longitudinal section of 
fresh dentin, five millimetres thick and almost dry upon the surface, had 
a resistance of thirty thousand ohms ; after drying and then saturating with 
a forty per cent, solution of cocaine the resistance was reduced to four 
thousand five hundred ohms, and after drying and saturating with a solu- 
tion of sodium chloride the resistance was reduced to three thousand and 
seventy ohms. 

From the statement of the foregoing facts, and the principles involved 
in applying the galvanic current to the human body for its cataphoric 
effects upon hypersensitive dentin, it becomes patent that the greatest care 
must be exercised in the selection of the initial degree of voltage ; in 
employing a relatively low amperage and carefully measuring the strength 
of current used ; in so controlling the current that it may be increased or 
diminished by imperceptible gradations ; in avoiding a breaking of the 



* Dental Cosmos, vol. xxxix. p. 90. 



212 OPERATIVE DENTISTRY. 

current, or too rapidly advancing the strength of the current, and in main- 
taining a moist condition of the cavity during the flow of the current. 

METHOD OF ADMINISTRATION. 

The first step in the application of the galvanic current for electro- 
cocaine anaesthesia by hypersensitive dentin is the isolation of the tooth 
to be operated upon by means of a rubber dam, which must be securely 
ligated at the cervix to prevent leakage of moisture or of the current. 
As an added precaution against leakage, the cervix of the tooth should be 
coated with some quick-drying varnish. If metallic fillings are present 
in the tooth to be operated upon, or in the approximal surfaces of the 
adjoining teeth included in the rubber dam, these should likewise be 
covered with varnish, or an extra rubber dam may be placed on the tooth 
to be treated for the purpose of insulating them, or otherwise the current 
would be dissipated from the cavity by being switched off or shunted by 
these conductors. 

The cavity of decay should be carefully irrigated with tepid water 
before adjusting the rubber dam, with the object of removing all the food 
debris and detached portions of disorganized tissue. 

It is not necessary to attempt to remove the carious dentin before the 
application of the cocaine, and the surface of the cavity need not be more 
than partially dehydrated. 

A pledget of cotton large enough to loosely fill the cavity is then satu- 
rated with the cocaine solution and placed in the cavity. The cathode is 
next placed in the hand of the patient or applied to the cheek, neck, or 
other suitable location. If the cathodal electrode is covered with sponge, 
this should be moistened with water, or, better, with a solution of sodium 
chloride. The anode is now applied to the cotton in the cavity and 
the current turned on, care being taken to start with the lowest voltage 
and weakest amperage. To obtain the best results from the cataphoric 
effect of the current the point of the anode (which should be made of 
platinum) should have a diameter as nearly the size of the cavity as possi- 
ble, but as this would necessitate purchasing a very large number and 
variety of platinum anodal tips, the writer uses instead platinum disks 
cut from ISTo. 30 gauge plate, and perforated with numerous holes for the 
ready passage of a reserve supply of the cocaine solution. These disks 
may be kept on hand in a variety of sizes and shapes at a very trifling 
expense. 

One of these disks is placed over the cotton, care being taken that it 
does not touch the dentin, and the anode applied to this. As a result of 
using electrodes with points whose cross-section nearly equals the diameter 
of the cavity, greater diffusion of current is secured than is possible with 
small points, unless metal disks are used in conjunction with them, as just 
suggested. 

Many operators have complained of their inability to secure complete 
anaesthesia over the whole surface of the cavity when employing catapho- 
resis, except by prolonged application. This is explained upon the sup- 
position that the surface contact area of the anode was too small to cover 



CATAPHORESIS. 213 

the area of dentin upon which it was desired to produce anaesthesia. It 
is a law of electricity that the current travels by the path of the least 
resistance. This in the vital tooth is by the organic matter in the tubuli 
and the contents of the pulp-chamber. Primary anaesthesia will therefore 
occur only over the radius covered by the positive pole, because the current 
passes directly from the anode to those tubuli which are in the direct path 
of the current. Secondary anaesthesia of the dentin may be secured by 
producing anaesthesia of the pulp, as no doubt occurred in some of those 
cases reported in which the anaesthetic effect of the treatment was secured 
only after a very long application of the current through a small pointed 
anode, while in others it was due to leakage of current or great density of 
the tooth. 

The anode should be constructed with a reservoir for holding a reserve 
supply of the solution, like Morton's tubular cataphoric applicator, or, 
better still, the syringe electrode of the S. S. "White Company (Fig. 321). 

Fig. 321. 




Syringe electrode. 

Teeth which are termed soft, or imperfectly calcified, especially chil- 
dren's teeth, respond more readily to electrococaine anaesthesia than do 
that class of teeth which are termed dense, or highly calcified, as the greater 
amount of organic matter in the former renders them better conductors 
of the electric current. 

When the current is first turned on to the tooth a slight, uneasy sensa- 
tion is experienced, but this immediately passes away, and the strength 
of the current may then be gradually increased a fraction of a milliampere 
at a time, or until the patient again becomes conscious of the current- 
pressure, but under no circumstances should it be advanced to such a de- 
gree as to be painful. The best results are obtained with low amperage 
— from one to three milliamperes as the maximum — and increasing the cur- 
rent very slowly. As anaesthesia advances the strength of the current may 
be more rapidly increased, but a current strength above five millianiperes 
is rarely required, and, finally, when this can be done without producing 
unpleasant sensations, anaesthesia may be considered as complete, the 
switch slowly carried back to the zero point, and the operation of cavity 
preparation commenced. 

With a current above five milliamperes there is danger of decomposing 
the chemic structure of the cocaine, or of producing coagulation of the 
albuminoid elements of the dentin by electrolysis. 

The period of application of the current may be stated to be from eight 



214 OPERATIVE DENTISTRY. 

to fifteen minutes in ordinary cases, but in teeth which are very dense a 
much longer period is sometimes required. 

The milliamperemeter should be carefully watched during the whole 
period of administration. Any rapid movement of the indicator, or a 
registration of a greater amperage than the dentin would admit, even at 
a higher voltage than that being used at the time, would be a sure sign 
that the current had found a path offering less resistance than the dentin, 
and if this is not corrected the administration will prove a failure. 

It is wise to always test the polarity of the terminals before applying 
the current. This may be done by bringing the ends of the terminals 
together, when the switch of the rheostat is on the first or second point, 
or they may be tested with wet litmus-paper, or paper moistened with 
solution of potassium iodide, when the positive pole will give the charac- 
teristic reaction. 

It has already been stated that the positive pole produces coagulation 
of the albuminoid substances contained in the tissues, and this may result 
in the dentin if too strong a current is used. This no doubt has been 
another source of failure in electrococaine anaesthesia. The use of coagu- 
lating remedies like carbolic acid should never be allowed in a cavity 
when cataphoresis is to be employed, as coagulated albumin is not a good 
conductor of electricity, and hence the diffusion of the cocaine by the 
current would be greatly retarded. 

GENERAL ANESTHESIA. 

The employment of general anaesthetics sometimes becomes necessary 
in the treatment of hypersensitive dentin, but they should be resorted to 
only in extreme cases, when all local means have failed, or when for some 
reason they cannot be employed. 

The general anaesthetics which have been used for this purpose are 
nitrous oxide, sulphuric ether, and chloroform. In the employment of these 
remedies for obtunding the hypersensitiveness of the dentin, the confidence 
and intelligent co-operation of the patient is a sine qua non, for the reason 
that a profound anaesthesia, or even loss of consciousness, is not necessary 
or even desirable if the best results are to be obtained from their employ- 
ment. During the^rs^ stage of anaesthesia, or just before the second, or 
stage of excitement, appears, sensation in the peripheral extremities of the 
nerves is greatly diminished or entirely obliterated, so that it becomes 
possible to make slight incisions in the skin or mucous membrane, or cut 
the most sensitive dentin without the slightest sensation of pain. 

During the first stage of anaesthesia the patient is drowsy and the mus- 
cles are relaxed, but conscious cerebration is not impaired. This is an im- 
portant consideration, for upon this fact rests the co-operation of the patient, 
and this is absolutely necessary if the operation is to be successfully per- 
formed. If the administration of the drug is continued to the develop- 
ment of the stage of excitement, the patient becomes unmanageable, and 
all delicate operative procedure is at an end ; while if profound anaesthesia 
is induced, the insensible condition of the patient renders that co-operation 
which is so desirable to the performance of such operations entirely out 



CAT A PHORESIS. 



215 



of the question. Furthermore, the upright position of the patient is 
necessary to the performance of these operations, which adds greatly to the 
dangers surrounding general anaesthesia, especially when chloroform is 
used. 

If, upon the other hand, it becomes necessary to remove a vital pulp, 
nothing short of a profound state of anaesthesia will suffice for a painless 
operation. 

Nitrous Oxide. — The use of nitrous oxide as a means of producing 
partial anaesthesia for the relief of pain in operating upon hypersensitive 
dentin has often been advocated and successfully employed. 

In the use of this agent the assistant should stand by the side of the 
chair ready to turn the gas on or off as the needs of the case may require. 
It should then be exx>lained to the patient that five or six deep inspira- 
tions will usually be sufficient to render the cutting of the dentin an 
entirely painless operation, but that this insensibility to pain will last only 
for two or three minutes, consequently it becomes necessary to operate 
very rapidly, and to this end the assistance and co-operation of the patient 
is earnestly solicited. Assurance should also be given that upon the 
slightest indication of a return of painful sensations the gas shall be 
again administered and this process repeated until the cavity has been 
prepared. With these explanations and assurances the confidence of the 
most timid patient will be secured and intelligent co-operation obtained. 

The inhaler (Fig. 322) should then be placed in the hands of the patient 
and instruction given in the method of applying it and of breathing. The 
gas is now turned on, and after five or 
six full inspirations have been taken, 
the inhaler may be removed and the 
sensitiveness of the dentin tested, 
and if it has disappeared, the exca- 
vation of the cavity may be proceded 
with, but if not, then three or four 
inspirations more may be taken, 
when the sensitivity of the dentin 
will be found to have been entirely 
overcome. As soon as the anaesthetic 
effect begins to pass off the inhala- 
tions should be renewed. 

Sulphuric ether is perhaps the most 
reliable general anaesthetic that can 
be employed for this purpose, as the 
obtunding effect upon peripheral 
sensation is more lasting than nitrous 
oxide, and far less dangerous than 
chloroform to the life of the patient. 

In administering ether care should 
be exercised in the selection of an inhaler to obtain one that will permit 
an abundant admixture of atmospheric air with the ether vapor, as by 
this precaution the irritation to the air-passages which is so common in 



Fig. 322. 





Flexible face-piece for inhalers. 



OPERATIVE DENTISTRY. 



Fig. 323. 




:._.;.! 



Allis's ether inhaler, 
rubber covered. 



the early part of ether anaesthesia is entirely obviated. The Allis inhaler 
(Fig. 323) is constructed with this object in view, and is the best invention 
of its kind that is manufactured. 

The time required to produce peripheral anaesthe- 
sia is about two minutes, and it lasts from two to five 
minutes. 

When ether is to be employed for its anaesthetic 
effect, the patient should be cautioned against eating 
just before the operation, as under such circumstances 
nausea and vomiting might occur. It is safest to 
take only a light meal three or four hours before the 
operation and no stimulants. With these precau- 
tions there need not be the slightest fear of any 
unpleasant symptoms attending or following the 
employment of ether for this purpose. 

Chloroform has been employed by some operators, 
while others have used the A. C. E. mixture, — alcohol 
one part, chloroform two parts, ether three parts. 

Chloroform and the A. C. E. mixture are not safe remedies to use 
for producing anaesthesia when the patient must be seated in an upright 
position, on account of the depressing effect of chloroform upon the action 
of the heart. Chloroform and its combinations are therefore contraindi- 
cated in all operations requiring the erect position as an essential feature 
of the procedure. 

Bonwill Method of Rapid Breathing. — The late Dr. Bonwill advo- 
cated several years ago a system of rapid breathing as a means of pro- 
ducing peripheral anaesthesia. The system consists of making very 
rapid and full inspirations and expirations — as though one were running 
— and keeping this up until the head becomes dizzy, when it is found that 
peripheral sensation has been greatly obtunded, and in some cases as com- 
pletely obliterated for a brief period as though some anaesthetic drug had 
been administered. The writer has occasionally employed this method 
with very great satisfaction in the treatment of hypersensitive dentin, and 
in a few instances has also extracted teeth which the patients have de- 
clared was done without producing the slightest painful sensations. 



CHAPTER XV. 



THE CLASSIFICATION OF CAVITIES. 



Carious cavities in the human teeth are usually divided into two gen- 
eral classes, — viz., simple and compound. These have been again divided 
into three general classes, — viz., 1, simple cavities upon exposed surfaces ; 2, 
simple approximal cavities; 3, compound cavities. 

The first division includes all of those cavities which are found upon the 
morsal, buccal, labial, and lingual surfaces of the teeth, which afford easy 
and direct approach to all parts of the cavity, and which are bounded by 
a continuous and unbroken wall of regular or irregular outline. 

The second division comprises all of those cavities which are located 
upon the approximal surfaces of the teeth, and are likewise bounded by a 
continuous and unbroken wall, but which do not, on account of their 
location, give ready and direct approach to all parts of the cavity, except, 
first, by separating the teeth, and secondly, by using instruments for their 
preparation which have been curved or bent at suitable angles. 

The third division is made up of all those cavities which are produced 
by a union of two or more cavities of the previous divisions, no matter 
whether they have been united by the extension of the process of caries 
or by surgical means. 

Weeks, in his u Manual of Operative Technics," offers the following 
classification of cavities : 

f A. — Cavities arising from structural imper- 
fections in pits and fissures. 



j All cavities on any surface 
other than proximate. 



-Cavities on labial, buccal, or lingual 
surfaces, caused by contact with 
secretions from diseased tissues, or 
the products of fermentation. 



Class 2. 



All cavities on the proximate 
surfaces of incisors and 
cuspids. 



A. — Cavities which do not involve the 
mesial or distal angle. 

B. — Cavities which involve the restoration 
of the mesial or distal angle. 



Class 3. 



f A. — Cavities which include the marginal 
ridge, but do not involve any sulci 
All cavities on the proximate or grooves upon the occlusal surface, 

surfaces of bicuspids and \ 

molars. B. — Cavities which involve not only the 

marginal ridge, but also the sulci 

I or grooves upon the occlusal surface. 



For the purposes of more accurately locating and describing each indi- 
vidual cavity, the following admirable division and classification has been 
taken from the " American Text-Book of Operative Dentistry," and slight 
changes made in it to give it a more comprehensive application. This 

217 



218 



OPERA TI V E D E N T fSTRY, 



classification is arranged progressively from the simplest form, A, to the 
most complex, W. 

The writer, however, takes the liberty of changing the terms occlusal 
and incisal, to morsal, as the latter term is equally applicable to both, and, 
as a multiplication of terms is to be avoided, there can be no valid objec- 
tion to the change. 

I. Simple Cavities upon Exposed Surfaces. 
Incisors' and Cuspids. Bicuspids and Molars. 

A. Labial D» Morsal. 

B. Lingual. E. Buccal. 

C. Morsal. F. Lingual. 



II. Simple Approximal Cavities. 


Incisors and Cuspids. 
G. Mesial. 
H. Distal. 




Bicuspids and Molars. 
I. Mesial. 
J. Distal. 


III. 


Compound 


Cavities. 


Incisors and Cuspids. 
K. Mesio-labial. 
L. Disto-labial. 
M. Mesio-lingual. 
N. Disto-lingual. 
0. Mesio-morsal. 




Bicuspids and Molars. 
R. Mesio-morsal. 
S. Disto-morsal. 
T. Morso-buccal. 
U. Morso-lingual. 
V. Mesio-clisto-morsal. 



P. Disto-morsal. 

Q. Mesio-disto-morsal. 



W. Bucco-linguo-morsal. 



Adopting this arrangement and classification as the best, the writer will 
adhere to it in all future descriptions of the location of carious cavities and 
of fillings. 

I. SIMPLE CAVITIES UPON EXPOSED SURFACES. 

Incisors and Cuspids. 

A Class. — Cavities upon the labial surface of the incisors and cuspids are 
usually found in two locations, — viz., at the cervix and near the morsal edge. 

Cavities at the cervix in the early stage of the carious process are 
generally in full view, and may consist of a softened condition of the 
enamel without visible loss of structure, or they may present any of the 
characteristics of the more advanced stages of the carious process. Fig. 
324, A, A, shows the form and location of this class of cavities. 



Fig. 324. 



Fig. 325. 



Fig. 326. 





The preparation of those cavities which occur at the cervix offer no 
serious difficulties, unless they extend beneath the gum. Under such cir- 
cumstances it becomes necessary, in order to gain a good view of the 



THE CLASSIFICATION OF CAVITIES. 219 

cavity and to properly prepare the cervical margin, to evert the overhang- 
ing gum. In the simpler cases this may be accomplished by pressing the 
gum away with a suitable instrument held in the left hand during the 
preparation of the cavity, care being exercised not to wound the gum, as 
the hemorrhage would obstruct the view. In the more complicated cases, 
where the edge of the gum has become inverted, it is necessary either to 
excise the inverted gum tissues or to evert them by packing the cavity 
over-full with gutta-percha and allowing it to remain for a few days. This 
procedure gives a clear field for the preparation of the cavity and the 
subsequent operation of filling. The adjustment of the rubber dam is 
sometimes a difficult procedure in these cases, but it can usually be ac- 
complished by exercising a due amount of patience. Absolute dryness of 
the cavity is imperatively demanded in a proper preparation, as well as 
for the subsequent operation of filling. Spoon excavators and round burs 
will be found to be the most useful instruments in the preparation of these 
cavities. Eetention may be obtained by slight under-cuts at the bottom 
of the cavity, at the cervical and morsal margins, and following its outline 
from one extremity to the other. Too much care cannot be expended in 
the preparation of the margins and terminal points of these cavities. They 
should be nicely bevelled, as shown in Fig. 325, and finished as smoothly 
as possible, so that the margin of the filling when finished will present a 
perfect outline. 

Cavities which occur upon the labial surface near the morsal edge are 
the result of developmental defects in the enamel in the form of pits and 
grooves, which cross the surface in nearly a straight line or surround or 
girdle the entire tooth at an equal distance from the morsal edge. This 
condition is shown in Fig. 326, A. 

These imperfections when quite shallow may be removed by corundum 
wheels and the surface polished. If, however, they are deep, it is better 
in the case of small pits to treat each one as a separate cavity, as illus- 
trated in Fig. 326, B, but when they are large, leaving but little tooth sub- 
stance between them, or in the case of deep grooves, it is better to convert 
them into a single cavity and fill it with gold, or set a porcelain inlay ; 
but when the groove girdles the tooth and is deep, the better plan for the 
sake of the cosmetic effect would be to cut off the tip and replace it with 
porcelain. 

B Class. — The vulnerable point on the lingual surface of incisors and 
cuspids is the fossa formed by the union of the marginal and basilar ridges. 
This fossa is often deep and not infrequently presents a pit or fissure in its 
deepest portion, which sometimes becomes the seat of caries, as shown in 
Fig. 327, A. 

As a rule, in the early stage of the disease these cavities are much 
deeper than they are broad. They are usually marked at the orifice by a 
dark spot, which often extends to a considerable depth, but rarely in- 
volves the pulp-chamber. 

In the preparation of these cavities in the incipient stage of the dis- 
ease the round bur is usually found to be the best instrument for the pur- 
pose. Eetentive shaping is rarely necessary, as the depth of the cavity 



220 OPERATIVE DENTISTRY. 

generally is greater than its diameter. The margins of the orifice, however, 
should be bevelled or countersunk, as in Fig. 327, B, by the use of a larger 
round bur, in order to insure perfect adaptation of the filling and to pre- 
vent bruising or fracturing of the enamel edge during the process of 
introducing the gold. 

In cavities presenting the later stages of the carious process, and which 
involve the greater portion of the lingual surface of the tooth and com- 
plicated with an inflamed or devitalized pulp, anchorage may be secured 
by enlarging the pulp-canal, as shown in Fig. 328 ; the preparation should 

Fig. 328. - 





After Dr. Marshall Webb. 

be conducted upon the same general principles as those adopted in the 
treatment of simple morsal cavities in the bicuspids and molars. 

C Class. — Cavities occurring upon the morsal edge of the incisors and 
cuspids are very rare, except as the result of fractures of the enamel or 
from mechanical abrasion or attrition. Fig. 329 shows such cavities in the 
superior incisors. These cavities are usually quite shallow, and being 
easy of access, no difficulty is experienced in their preparation. 

Care, however, must be exercised in the preparation of the enamel mar- 
gins to extend the bevel to the marginal edge, so as to prevent fnture 
fracturing of the enamel. Failure in this direction often ruins an other- 
wise substantial and beautiful operation. Retentive shaping is also an 
important feature in this class of cavities. The strain is often very great 
upon such fillings, particularly in those cases where the teeth have been 
shortened by excessive mechanical abrasion and the normal 
Fig. 330. length is to be restored ; consequently every effort should be 
made to give the filling the greatest security by proper reten- 
tive shaping. The drilling of retaining- pits is not to be recom- 
mended when the location and the extent of the cavity will 
permit it to be slightly enlarged at the bottom. This enlarge- 
ment should extend in all directions, giving a dovetail or, 
more correctly, an inverted-cone form to the cavity (Fig. 330). 
Caries sometimes occurs as a result of developmental defects 
in the enamel ; such cavities are to be prepared and filled like other cavi- 
ties of the same size and form. 

Bicuspids and Molars. 

D Class. — This class comprises all of those cavities which occur in the 
pits and fissures upon the morsal surface of the bicuspids and molars. 
Their location is such that an unobstructed view can be obtained of all 
parts of the cavity, and they are easily accessible to direct instrumentation. 
The difficulties in operating are somewhat increased in the posterior part 



THE CLASSIFICATION OF CAVITIES. 221 

of the mouth, especially in the superior third molars, but with properly 
curved excavators, the right-angle hand-piece and reflected light, the 
preparation of such cavities becomes a comparatively simple matter. 

The lower first bicuspid usually presents the simplest form of cavity upon 
the morsal surface of the teeth. The triangular ridge connecting the 
buccal with the lingual cusp is usually very large and prominent, and 
under such circumstances the mesio- distal sulcus is not strongly marked 
or is wanting altogether. The triangular ridge forms with the mesial and 
distal marginal ridges the mesial and distal pits. These pits are usually 
the first part of the tooth to be attacked by caries. Caries attacking the 
pits form simple roundish, penetrating cavities, which may be opened and 
prepared separately with round burs. 

On the morsal surface of the upper first and second bicuspids, caries 
usually begins in the fissure between the cusps (Fig. 331). It sometimes 
presents as a simple dark line, into which the sharp point of an explorer will 
hardly enter, while at a later period the 
cavity will have been increased in size _.. . , , rG ' ' ' ., . , 

Disto-buccal >«&v .Mesiobuccal 



by the undermining of the enamel and fissure. \V^ V // ' issure ' 

the disintegration of its margins, so that ( /""^T suicuT. 

an excavator will readily pass through Wst<>1 K£ ^%J^^ fesurt" 11 ^* 1 
the entire length of the fissure. 

These cavities in their earlier stages may be opened with the tapering 
fissure-burs ; in the later stage enamel-chisels will be found most useful. 
After the cavity has been opened, the decay should be thoroughly removed 
and a proper retentive shape given to it. Especial care should be given 
to the terminal pits and to the triangular grooves or fissures. The latter 
should be cut out to their fullest extent, or until all suspicious tissue has 
been removed. 

The margins should then be carefully bevelled and the cavity is ready 
for the filling (Fig. 332). The student should be cautioned against sacri- 
ficing more of the sound tissue than is really necessary to gain the object in 
view. Whenever possible the mesial and distal marginal ridges should 
be maintained intact, as these bind the buccal and lingual cusps together, 
and if they are destroyed, the crown is greatly weakened and the cusps 
are liable to be fractured and broken away. Sharp angles are to be 
avoided, especially in the outline of the cavity margins. All angles 
should be rounded out, and the outline of the cavity should present, when 
finished, a series of graceful curves. 

The morsal surface of the lower second bicuspid usually presents three 
cusps, which are divided by the triangular groove, the termination of each 
arm of the groove ending in a pit. The most vulnerable points in this groove 
are at its centre, where the arms of the groove meet, and at the terminal 
pits. Caries occurring in any part of the groove will make it necessary 
to cut it out in all directions as the only way to insure the tooth against 
a recurrence of the disease in this location. 

Upon the morsal surface of the upper first and second molars there are 
two points at which caries is liable to occur, one known as the mesial 
fossa, the other as the distal fossa, and situated respectively upon the mesial 



222 OPERATIVE DENTISTRY. 

and distal sides of the oblique ridge (Fig. 333). These fossae are sometimes 
traversed by a broad sulcus or a deep fissure. The fissure of the mesial 
fossa often assumes a triangular form. To insure success it is necessary to 
cut out the fissures to their utmost limits. The instruments used for pre- 
paring these cavities should depend upon the progress which has been 
made by the disease ; when limited' in extent, small-pointed fissure-burs 
are the best for opening the cavity ; in the later stages the enamel- chisels 
will be found most useful. The margins should be so prepared as to leave 
smooth, strong bevelled edges (Fig. 334). 

Occasionally the mesial and distal cavities will be found united beneath 
the oblique ridge. Under such circumstances the bridge between the 
orifices of the cavities should be cut away and the two cavities converted 
into one. Fig. 335 represents the prepared cavity. The mistake of 

Fig. 332. Fig. 333. Fig. 334. Fig 335. 






leaving the bridge of enamel and dentin between them is often made, even 
by good j>ractitioners, but such operations sooner or later come to grief, 
either from fracture during the operation of filling, or later from the stress 
of mastication. 

The morsal surface of the upper third molar is usually surmounted by 
only three cusps, and has, like the lower second bicuspid, a single central 
fossa and a triangular fissure radiating from the centre of the fossa and 
passing between the cusps. This cavity should be so prepared that when 
finished it will be triangular in form, with the points of the angles rounded 
out so that the filling- material may be perfectly adapted to the walls and 
margins. Fig. 336 represents the prepared cavity. Failure more often 
occurs in these cases than in any other of their class, for the reason that the 
fissures are not always cut out to their utmost limit and perfectly sound 
enamel and dentin reached in every part before the filling is introduced. 
There is also more difficulty experienced by the patient in keeping these 
teeth perfectly clean after the operation ; especial care should therefore be 
exercised to make the operation as nearly perfect as possible, so that no 
open point of attack may be left for the entrance of the micro-organisms 
of decay. 

The morsal surface of the lower first and third molars each present five 
cusps, — three buccal and two lingual, — with sulci running between them. 
A cavity, therefore, occurring upon this surface and following the sulci 
would present a five-pointed or pentagonal outline (Fig. 337). 

As a rule, chisels are the most serviceable in opening these cavities, 
the extremities of the fissures being followed with the pointed fissure-bur, 
and finished with larger round ones. 

In following the fissure it is better to go a little too far into the sound 
tissue than to fail to remove every particle of the decayed or softened 
dentin or enamel. Thoroughness in the preparation of a cavity never 



THE CLASSIFICATION OF CAVITIES. 



223 



gives a greater reward than in these teeth. Fig. 338 shows the finished 
cavity. 

The morsal surface of the lower second molar presents four cusps with 
cruciform sulci separating them. 

Caries is most often found at the point of meeting of the sulci (Fig. 
339, A). 

In preparing a cavity of this character the sulci should be cut out to 
their extreme limits, the sharp angles at the intersection of the sulci 



Fig. 337 




Disto-buccal 
fissure. 



Mesio-buceal 
fissure. 



Fig. 338. 





Lingual fissure. 

rounded out, and the margins bevelled. Sharp angles, if left at the inter- 
section of sulci, are liable to be bruised and fractured during the introduc- 
tion of a gold filling ; these angles should therefore be properly rounded 
out, as shown in Fig. 339, B. Occasionally the morsal surface of the bicus- 
pids and molars will be so extensively decayed as to invol v T e the cusps, 
making a large open cavity extending over the whole morsal surface of 
the tooth. In preparing such cavities the morsal edge of the cavity should 
be first ground down with corundum wheels until strong walls are reached. 
The decayed tooth-structure should then be removed, the cavity given a 
shape as shown in the illustration of the longitudinal section of a tooth 



Fig. 340. 



Fig. 341. 



Fig. 339. 






Longitudinal section. 



(Fig. 340), and the edges of the cavity nicely bevelled towards the cavity. 
Fig. 341 shows such a cavity prepared for the filling in a bicuspid tooth. 

When the pulp is involved, this should first be removed and the canals 
filled, as described in Chapter XXVII. The pulp-chamber in these cases 
may be utilized for additional anchorage. 

E Class. — This class includes all of those cavities which occur upon the 
buccal surface of the bicuspids and molars. Caries is rarely found upon the 
buccal surface of the bicuspids, except at the cervix. These cavities are 
usually long and narrow, and follow the line formed by the free margin of 
the gum, and often extend beneath it. They are usually half-moon shaped 



224 OPERATIVE DENTISTRY. 

or elliptical in form, as shown in Fig. 342, A, and not infrequently in- 
volve the approxiinal surfaces by their lateral extension. 

The upper molars have nearly the same exemption from caries upon 
the buccal surface, cavities appearing most often at the cervix ; the third 
molar being more often affected than the others. The outlines of the cavi- 
ties formed at this point are similar to those occurring in the bicuspids. 
Cavities occurring upon the buccal surface which do not involve the cervix 
are usually long, narrow, and elliptical in form, the long axis having a 
mesio-distal direction, as shown in Fig. 343, A. Occasionally, however, 
cavities will be found in the buccal groove, located well towards the cervix. 
In the lower molars this condition is much more frequently found, and the 
cavities are sometimes quite large, extending to and involving the inorsal 
surface, forming a compound cavity. 

As the disease extends it frequently passes beneath the free margin of 
the gum, thus increasing the difficulties in preparing the cavity for the 
reception of the filling. These difficulties may be overcome by adopting 
those measures already described in the preparation of labial cavities in 

Fig. 342. 

A B 




the incisors and cuspids. Round engine burs and spoon excavators are 
the most suitable instruments for preparing this class of cavities. The 
right-angle hand-piece will also be found very useful in preparing the 
cavities in the molars, particularly those located in the second and third 
molars. The retentive form given to them should be that of slight under- 
cuts at the base of the cavity, in a line parallel with its long axis ; but 
sometimes it is well to make slight retention pits in the mesial and distal 
extremities of the cavity. The angles should be rounded out and the mar- 
gins slightly bevelled, as shown in Fig. 342, B, and Fig. 343, B, in order 
that perfect adaptation of the filling- material may be secured. 

Simple cavities occurring in the buccal groove of the upper and lower 
molars should be prepared with a slightly under-cut form. The prepara- 
tion of those cavities which are compound in their nature will be described 
under T Class. 

F Glass. — Caries rarely occurs upon the lingual surface of the bicuspids. 
The molars, however, present a slightly increased liability. Cavities upon 
the lingual surface of the upper and lower molars occur in the lingual groove, 
at the cervix, and in the upper first molars in the fissure which exists be- 
tween the mesio-lingual cingule or fifth cusp, when this is present, and 
the crown. 

The degree of exemption from caries possessed by the lingual surface 
of the bicuspids and molars is doubtless due to their smooth and rounded 



THE CLASSIFICATION OF CAVITIES. 225 

surfaces, the friction of the tongue in speech and mastication, and the 
more abundant presence of the oral secretions, which have a tendency to 
keep them clean. 

The most common location of caries upon these surfaces is the Ungual 
groove of the upper first molar, which often presents a deep fissure termina- 
tion in a pit about midway between the linguo-morsal margin and the 
cervix. Caries usually appears first in the pit, and sooner or later extends 
through the entire length of the fissure, passing over onto the morsal sur- 
face and forming a compound cavity. When the groove is shallow and 
not traversed by a fissure, the cavity is often confined to the terminal 
pit. 

Caries occurring at the cervical margins of the lingual surface of the 
bicuspids and molars are, from the difficulties presented by their location, 
often troublesome to properly prepare and fill. They should be prepared 
and filled after the same manner as those cavities occurring upon the 
buccal surfaces of the same teeth. 

Cavities occurring in the fissure between the mesio-lingual cingule and 
the crown should be opened through the entire length of the fissure as 
the only means of preventing extension or a recurrence of the disease. 
No especial description of the preparation is necessary in this class of 
cavities. They should be treated and filled according to general principles. 



II. SIMPLE APPROXIMAL CAVITIES. 

Incisors and Cuspids. 

G and S Classes. — The location at which caries most frequently occurs 
upon the approximal surfaces is not at the actual point of contact of these 
surfaces, but in a location a little nearer to the cervix, just beyond the 
point of the V formed by the interapproximal space, — in other words, just 
where fluid and semifluid debris would be held by capillary attraction. 
Another location of caries of the approximal surfaces is just at the margin 
of the gum where the festoon forms the base of the interaj)proximal space. 
Occasionally two such decayed spots will be found upon a mesial or distal 
proximate surface ; and it is a very common circumstance to find the ap- 
proximating surfaces of the teeth decayed in exactly the same locations. 

In the incisors and cuspids the carious spot is at first round in form, in 
the bicuspids oval, and in the molars it is oblong. (Jack.) In the later stages 
of the disease the cavities assume shapes more in accordance 
" with the form of the proximate surfaces of the tooth,— as, for 
instance, in the incisors and cuspids the cavities will be trian- 
gular in outline, the base of the triangle being towards the cervix, 
as shown in Fig. 344, while in the bicuspids and molars the form 
will be more nearly that of a rectangle. 

The mechanical difficulties presented in the treatment of 
simple proximate cavities of the anterior teeth are only those arising from 
their inaccessibility. In order to obtain an unobstructed view of the 
cavities, temporary separation of the teeth is a necessity. But sometimes, 
even after thorough separation, a good view of some parts of the cavity 



226 



OPERATIVE DENTISTRY. 



cannot be secured without cutting away a portion of either the lingual or 
the labial wall. The lingual wall, for the sake of the cosmetic effect, should 
be sacrificed in preference to the labial, as gold fillings upon the labial sur- 
faces are at the best blemishes which seriously mar the beauty of the 
natural tooth. On the other hand, if the cavity is large and the labial 
wall is much weakened, the success of the filling, and perhaps the salva- 
tion of the tooth, will depend upon the thoroughness with which this 
weakened wall is removed ; but, nevertheless, care should be exercised not 
to remove more than is necessary to obtain strong margins. 

Large cavities often come dangerously near to the pulp ; great careful- 
ness should therefore characterize the work of their preparation, that this 
organ may not be exposed by an unneccessary sacrifice of sound dentin. 

Small chisels will be found most useful in opening all simple proximal 
cavities, while small hatchet excavators having bayonet-shaped shanks, and 
cow-horn spoons, as shown in Figs. 345 and 346, will, as a rule, gain access 

Fig. 345. 




to all parts of the cavity and permit the ready removal of the decayed 
dentin. 

Eound burs of suitable sizes will be best adapted for trimming and 
shaping the cervical margin of the cavity, which should be so prepared as 
to leave a strong and but slightly under-cut or perfectly flat wall, care 
being taken, if the cavity reaches the cervix, not to leave a narrow rim 
of enamel which would be likely to be fractured in condensing the gold 
against it. The enamel margins should always be carefully bevelled with 
small chisels and polished with file-cut burs and Arkansas stones. All 



THE CLASSIFICATION OF CAVITIES. 



227 



angles should be rounded with chisels, burs, or stones. Fig. 347 represents 
the prepared cavity. 

Eetentive shaping of these triangular-formed cavities requires that three 
points of anchorage be obtained, two at the base of the triangle in the angles 
and one at the apex. These may be formed by deepening the 
angles at the bottom of the cavity at the cervix with a small, Fig. 
round bur, and that in the apex at the morsal edge with a small 
hatchet excavator. 

Shallow undercuts may also be used as a means of retention 
in the smaller cavities. Retention grooves, however, should 
never be cut in the labial and lingual walls, as these weaken the 
walls to a serious extent. 

Cavities which extend beneath the gum should be treated beforehand 
by the removal of the overhanging gum tissue, so that a clear and unob- 
structed view of the cervical margin may be obtained. 

Occasionally, either from the size or location of the cavity, it approaches 
very near to the morsal edge (Fig. 348, A), rendering the unsupported 
enamel very liable to fracture. Under such circumstances it is better to 
remove the weak corner and convert the cavity into a compound one, as 
illustrated in Fig. 348, B, rather than to attempt its conservation and have 
it break away at some future time under the stress of mastication. 



Fig. 348. 



Fig. 349. 




, ,^-M-- A 



Black has suggested as a means of anchorage in these cases the exten- 
sion of the cavity upon the lingual surface in the form of a dove-tail, as 
shown in Fig. 349, A, rather than by forming a retaining pit or groove at 
the morsal edge of the tooth. 

Such an extension need not necessarily weaken- the tooth to any 
appreciable degree if it is not formed too near the morsal edge or cut 
too deeply into the dentin, while it adds greatly to the retentive power of 
the cavity at the point where the greatest strain comes in biting or during 
mastication. 



Bicuspids and Molars. 

I and J Glasses. — Small cavities upon the mesial and distal surfaces of 
the bicuspids and molars present considerable mechanical difficulty in their 
preparation. Figs. 350 and 351 illustrate cavities of this character. These 
difficulties, which are mainly those of inaccessibility, are greatest when 
the teeth maintain their normal approximation. They can, however, 
usually be overcome by making temporary separation, the space being 
made as wide as the circumstances of the case will permit. The wider the 



228 



OPERATIVE DENTISTRY. 



space obtained the greater will be the ease with which these cavities can 
be approached. Figs. 352 and 353 represent the prepared cavities. 

When ready access cannot be attained in this way, one of two other 
methods must be adopted, — either to convert them into compound cavities 
by cutting through the morsal surface until the cavity is reached, or by ex- 
tending the cavity to the buccal surface. The former of these two methods 
should receive the preference as being the least difficult to accomplish, 
and makes the strongest operation from the mechanical stand-point ; 
whereas in the latter method the difficulties are increased by reason of the 
limited amount of space in which to operate, while the overlying enamel at 
the morsal surface of the approxinio-buccal angle will always remain an 
element of weakness as a result of its being undermined in extending the 
cavity to the buccal surface. Sometimes, however, this is the only method 
by which the cavity can be reached. Simple cavities upon the approximal 
surfaces of the bicuspids and molars more often fail after being filled than 
any other class of cavities. This is no doubt largely due to the fact that 
operations in these locations do not permit of ready access to all parts of 
the cavity, and cannot therefore be so thoroughly and perfectly prepared 
as those in which these difficulties do not have to be overcome. 



Fig. 350. 



Fig. 351. 




Fig. 352. 



Fig. 353. 




In the opening of these cavities small, straight, and acute-angle chisels 
will be found very useful, while the removal of the decay and the prepara- 
tion of the margins can best be accomplished with round burs in the 
straight or right-angle hand-piece, according to the mesial or distal loca- 
tion of the cavity. 

Distal cavities are the most difficult to reach with instruments, and the 
only view that can be obtained of them is by reflection in the mouth 
mirror. This naturally adds to the difficulty in preparation and filling. 

Eetentive form may be given to the cavity by slightly enlarging it at 
its base, or undercutting at two opposite points. This may be accom- 
plished with small hoe excavators of obtuse and acute angles and small 
hatchets. 

In preparing and finishing the enamel margins, advantage can be taken 
of the natural outward radiation of the enamel- prisms to give the proper 
bevel to the orifice of the cavity. 

In large cavities upon the approximal surfaces which approach the 
morsal surface it is best to cut through this surface and convert it into 
a compound cavity, rather than to run the risk of fracture of the enamel 
at a later period and consequent loss of the filling. 



THE CLASSIFICATION OF CAYJTIES, 220 

III. COMPOUND CAVITIES. y 

Incisors and Cuspids. 

K and L Glasses. — Compound cavities are formed by the union of two or 
more simple cavities located upon different surfaces of a tooth. The simpler 
class of compound cavities are those located upon the mesio -labial and disto- 
labial surfaces. Fig. 354 shows such cavities in the superior incisors. 
Teeth thus affected are generally of faulty organization and are markedly 
predisposed to caries. Such cavities are usually formed by the joining of 
an approximal cavity with one at the cervical margin of the labial sur- 
face. Sometimes the cavities will be separated by a narrow isthmus of 
more or less infected enamel or perhaps of sound tissue. In either case 
the cavities should be connected, the isthmus cut away, and the enamel 
edges straightened before the margins are finally finished for the filling. 
Acute angles, uneven marginal lines or peculiarities in form, are to be 
avoided in all operations that occupy a conspicuous position in the ante- 
rior part of the mouth, for the reason that things peculiar attract the 
attention much more quickly than those which follow the general order. 

Temporary separations are commonly necessary in order to gain access 
to that portion of the cavity which is located upon the proximal surface. 

Fig. 354. Fig. 355. Fig. 356. Fig. 357. 





In the preparation of these cavities especial pains should be taken with 
the enamel margins, particularly at the cervical border and at the angle 
formed by the union of the cavities, as these are the points at which fail- 
ures most frequently occur in this class of fillings. 

Eetention may be secured by grooves cut in the walls at the base of 
the cavity, and by a single shallow retaining pit at each extremity of the 
cavity to assist in starting the filling. Fig. 355 shows such cavities pre- 
pared. 

Separate descriptions for the preparation of these two classes of cavities 
are not necessary, as one does not possess a peculiarity which is not com- 
mon to the other, except that of location, and this does not materially 
affect the method or the difficulties of the operation. 

MandN Glasses. — Compound cavities of these classes are located upon 
the mesio-lingual and disto-lingual surfaces of the incisors and cuspids. These 
cavities are usually formed by the union of a proximate cavity with one 
occurring in the basilar pit or sulcus connected with it, as illustrated in 
Fig. 356. Such cavities are most often found in the central and lateral 
incisors, and from their location and the relative inaccessibility offer con- 
siderable more difficulty in their preparation and filling than those involv- 
ing the mesio-labial or disto-labial surfaces. Fig. 357 represents the pre- 
pared cavity. When two simple cavities exist upon the proximate and 
lingual surfaces of these teeth which nearly approach each other, it is better 



230 OPERATIVE DENTISTRY. 

to join them as in the manner described in K and L Classes, rather than 
to fill them as separate cavities with only a narrow isthmus of healthy den- 
tal tissue between them, for sooner or later this tissue will be attacked by 
caries and the whole operation prove a disastrous failure. 

Eetention is best gained by undercutting the lingual cavity and slightly 
grooving the cervical wall. Grooves in the labial or lingual walls of the 
cavity are not admissible, as they weaken these walls and increase the 
dangers from fracture. Occasionally it becomes necessary to connect a 
mesial and distal cavity with one upon tho lingual surface. This is to be 
avoided whenever possible, for the reason that when both of the marginal 
ridges have been destroyed the crown of the tooth has lost its strongest 
support, and is very liable to be fractured whenever a severe strain comes 
upon the lingual surface near the morsal edge. 

and P Classes. — Cavities of these classes are generally confined to the 
incisor teeth, and are formed by a union of a mesial or distal cavity with 
one upon the morsal edge. They do not, as a rule, appear until after 
middle life, the morsal cavity being produced by attrition and gradually 
deepening until it becomes connected with a proximate cavity produced 
by decay. Occasionally through accident a mesio- morsal or disto-niorsal 
angle of a tooth is lost (Fig. 358), necessitating the formation of a cavity 

Fig. 359. Fig. 360. 





involving both the proximate surface and the morsal edge before restora- 
tion of the lost part with gold can be undertaken. 

The preparation of these cavities involves no principle which has not 
already been emphasized. Each cavity may be prepared separately, after 
the manner already described, but especial care should be exercised in the 
preparation of the angle formed by the junction of the two cavities. The 
labial portion should be cut away just as little as is compatible with 
strength and the removal of unsound tissue. The lingual wall, which is 
more liable to be fractured by stress of mastication, may be removed more 
freely and its contour restored by the filling. 

The enamel margins of the morsal portion of the cavity should be so 
bevelled that when the filling is inserted they will be protected by the 
gold from the dangers of fracture. When the enamel plates are very thin, 
they should be shortened and the normal length of the tooth restored with 
gold. The necessary retentive shaping may be obtained by slightly under- 
cutting the morsal cavity and grooving the cervical wall of the proximate 
cavity. Additional retention may be secured by forming shallow retain- 
ing pits at the opposite ends of the groove at the cervical wall. 

In certain cases it may become necessary, in order to obtain firm anchor- 
age for such fillings, to form an extension-arm, as shown in Fig. 359, A, 
or by giving the extension a curved or hooked form. These are ingenious 



THE CLASSIFICATION OF CAVITIES. 231 

methods of retention, and afford a means of anchorage, which in many 
cases, on account of the thinness of the tooth, could not be secured so 
well in any other way. 

Q Class. — Cavities belonging to this class are formed by the union of 
mesial, distal, and morsal cavities in the incisors and cuspids, as shown in 
Fig. 360. They differ from O and P Classes principally in extent, but 
the peculiarity of the form of the combined cavities makes their prepara- 
tion and subsequent filling an operation requiring the greatest care and 
skill. 

The methods of preparation and the securing of anchorage are in 
nowise different from those employed in the preceding class of cavities, 
but the exercise of a trained judgment is nowhere of greater value or more 
severely taxed than in the proper preparation and filling of these cavities. 
A thin or checked enamel wall, a deep undercut, an acute angle, or a 
rough or improperly bevelled margin are sufficient to cause the failure of 
a«n otherwise perfect operation. 

Bicuspids and Molars. 

B and S Classes. — These classes comprise all of those cavities in the bi- 
cuspids and molars which are formed by a union of mesial or distal with 
morsal cavities of decay, and represent classes which are the most common 
and in many ways the most difficult to successfully fill. Fig. 361 illus- 
trates this class of cavities. Failures are common, after a few years, in 
this class of operations, even in the hands of the very best operators ; 
therefore it cannot be entirely the result of faulty manipulation, as some 
writers would have the profession believe. The vulnerable points in fill- 
ings of this class are the cervical margin, and "that margin which is 
nearest to the operator during the process of the introduction of the gold." 
(Johnson.) These are the points also which clinical experience teaches 
are most often the seat of secondary caries, and they are no doubt in many 
instances caused by imperfect preparation of the cavity, faulty adaptation 
of the gold to the cavity walls, or lack of proper restoration of the inter- 
proximal space by adequate contouring. 

Fig. 363. 






There are, however, other factors entering into the causation of sec- 
ondary caries as important as those just mentioned, — viz., the character of 
the tooth-structure, the natural shape of the approximal surfaces, the 
hygienic condition of the mouth, the state of the general health, the char- 
acter of the secretions, and the activity of the zymogenic organisms of 
decay. 

While these conditions are operative in all parts of the mouth, the 
latter are, nevertheless, more active in some locations than in others. 



232 OPERATIVE DENTISTRY. 

Therefore, on account of the greater difficulties presented in keeping the 
approximal surfaces of the bicuspids and molars free from food debris, 
recurrence of caries is by that much more liable to occur in these loca- 
tions. 

Ordinary cavities in these locations present no serious difficulties either 
in their preparation or filling. 

Such fillings, however, are subjected to great mechanical strain during 
mastication, and therefore require to be very firmly anchored. Eetention 
may be secured by a shallow groove at the cervical margin with shallow 
pits at each extremity of the groove, and giving a dove-tail form to the 
morsal portion of the cavity, as shown in Figs. 361 and 362. In molars 
having mesio- morsal or disto-morsal cavities firm anchorage may be secured 
by extending the buccal or lingual fissures, as shown in Fig. 363. 

Large cavities, however, which extend beneath the margin of the gum, 
and have involved portions of the buccal, lingual, or morsal surfaces, often 
present difficulties which require a very high order of mechanical knowl- 
edge and of manipulative skill to successfully overcome. 

In the preparation of all approximal cavities temporary separations 
are imperatively demanded, and these should be as wide as the surround- 
ing conditions will permit. 

The gum, if it overhangs the cervical margin, should be previously 
forced out of the way with gutta-percha or cotton. After the cavity 
has been roughly prepared, the rubber dam should be adjusted and the 
final preparation completed. The greatest care should be exercised to 
obtain strong walls, rounded angles, nicely finished margins, and firm 
anchorage. 

T Class. — This class of cavities is formed by a union of morsal with 
buccal cavities of decay, as shown in Fig. 364, and are more frequently 
found in the lower molars than in the upper. They have their origin in 
the pit and developmental groove of the buccal surface and 
Fig. 364. in the fissures of the morsal surface. These cavities are often 
found united at their bases while still separate at their orifices. 
To insure a satisfactory result in filling such cavities it be- 
comes necessary to unite them by cutting away the bridge of 
tissue which connects their orifices. To attempt to conserve 
this bridge of tissue, which would be more or less infected, 
and the enamel without the proper support of sound dentin, 
would only invite failure of the operation by the danger from fracture 
during the introduction of the filling, or later under the stress of force 
applied in mastication. In those cases in which the bases of the cavities 
have not been united by the carious process, but in which union has taken 
place at their orifices b}^ extension of the disease along the buccal groove, 
care should be exercised not to cut away more of the sound tissue than is 
necessary to give proper retentive shape to the cavity, in order that the 
tooth may not be unnecessarily weakened. Strong walls and well bevelled 
margins are nowhere more imperatively demanded than in this class of 
cavities, as the strain upon these teeth during mastication is often very 
great. 




THE CLASSIFICATION OF CAVITIES. 



233 



Fig 




TJ Class. — Cavities of this class are formed by a union of a morsal with. 
a lingual cavity of decay. They are very rare except in the first and 
second upper molars. They have their origin in the pit and 
lingual groove which separates the mesio-lingual and disto- 
lingnal lobes, and a cavity in a fissure of the morsal surface 
(Fig. 365). As a rule, these cavities do not involve the lingual 
surface of the crown to the same extent that the buccal sur- 
face is involved in the preceding class. Sometimes the cavity 
upon the morsal surface extends but very slightly upon the 
lingual surface, while at others it extends deeply towards the 
cervix. When the cavity upon the lingual surface is large, the disto- 
lingual cusp is liable to be much weakened by being undermined. Under 
such circumstances the cusp had better be cut away and the occlusion 
restored by contouring. The same general principles govern the prepara- 
tion of these cavities as in the preceding class. 

V Class. — Cavities which belong to this class are formed by the union 
of mesial, distal, and morsal cavities in bicuspids and molars, as illustrated 
in Fig. 366. The size of the combined cavities is often very large, and in 
those cases in which either or both the buccal and lingual walls are weak, 
it is better practice to restore the usefulness of the 
tooth by inserting a suitable artificial crown than by 
the introduction of a filling which in a few years 
would, in all probability, be lost from fracture of 
one of the two remaining walls of the tooth. Under 
favorable conditions, in cases where the walls are 

strong, a properly inserted filling would be the best means of restoring the 
usefulness of the tooth. No especial difficulties surround the preparation 
of this class of cavities other than those which arise from their size. The 
method of preparation is the same substantially as that described for E 
and S Classes. 

W Class. — Cavities of this class are somewhat rare and are formed by a 
union of buccal, lingual, and morsal cavities, usually in the lower molars. 
These cavities do not present as great difficulties in their preparation and 
filling as many of those which have been already considered. The same 
general principle should govern their preparation and filling as are indi- 
cated for T Class. 



Fig. 366. 




CHAPTEB XYI. 

PREPARATION OF CAVITIES. 

The first important element in the treatment of carious teeth by filling 
is the proper preparation of the cavity for the reception of the material 
which has been selected for the purpose ; the second is the introduction of 
the filling-material in such a manner as to hermetically seal the cavity ; 
and the third, to so finish the filling as to leave perfect margins and a highly 
finished surface. 

If these three conditions are successfully obtained, the operator has 
fulfilled his obligation to his client, and if failure follows, it will be due to 
conditions of health and local environments over which he has no direct 
control. 

Guilford says, "As many fillings fail from lack of thoroughness in the 
preparation of the cavity as from any other cause." 

Ottolengui asserts, ' ' When a cavity is filled scientifically the tooth is 
safer than ever, because the vulnerable point is now occupied by a ma- 
terial which will resist destruction by caries. If decay occurs along mar- 
gins, it is because those margins were improperly made, either as to 
shape or position, or else because the filling was unskilfully inserted or 
finished." 

Black also lays great stress upon the proper preparation of the cavity, 
and enunciated the broad principle of extension for prevention. 

He says, ' ' A large proportion of decays occur in the proximate sur- 
faces of the teeth, and for many years it has been noted that recurrence 
of decay after filling is especially liable to occur in these surfaces. A 
reason for this has generally been sought in some fault in the management 
of the enamel margins. The enamel margins about a filling should always 
be regarded as a weak point, and should be guarded in every possible way 
against the danger of a recurrence of decay. One great difficulty has 
been that the same rule of extension for prevention has not been applied to 
the proximate surfaces as has obtained in the grinding surfaces. Exten- 
sion for prevention is extension of the enamel margin from a line of greater 
liability to caries to a line of lesser liability. Or, to change the phrase, it is 
to cut the enamel margins from lines that are not self- clean sing to lines 
that are self-cleansing." 

Parreidt says, ' ' One step is as important as the other. The slightest 
defect in either makes the result entirely questionable. Thoroughness and 
especially care are most important essentials expected of an operator who 
undertakes filling of teeth." 

Tomes, in speaking of the importance of a proper preparation of the 
cavity, says, "Upon the proper performance of this the ultimate success 
of the operation will, in great measure, depend." 
234 



PREPARATION OF CAVITIES. 235 

Statements of this character, which are based upon practical expe- 
rience, might be multiplied almost indefinitely, but a sufficient number 
have been cited to indicate that there is but one opinion held upon the 
subject by the best authorities. 

The student, therefore, will be wise if at the very outset of his profes- 
sional career he determines to profit by the experience of those who have 
learned — perhaps by a long series of failures — that the proper preparation 
of the cavity is as essential in the filling of a tooth as are proper founda- 
tions in the building of a house. With solid foundations to build upon, 
the superstructure may be reared with the certainty that when the stress 
comes it will stand the test. 

In the preparation of a carious cavity for the reception of a filling 
each step in the operation should be thoroughly and conscientiously per- 
formed, so that when it is completed all infected tissue will have been 
removed and the cavity be in the best possible condition for the reception 
and retention of the filling. 

The general principles involved in the preparation of cavities are 
naturally divided into four progressive stages : 

1. Opening the cavity. 

2. Eemoving the decay 

3. Eetentive shaping. 

4. Forming cavity margins. 

Opening the Cavity. — The first step in the preparation of all cavities 
is to freely open the orifice by cutting away all overhanging edges of 
enamel, so that wherever possible the walls may be readily approached 
from all points. 

Perhaps the most important step in the preparation of carious cavities 
is to cut away all overhanging enamel margins which are not supported by sound 
dentin, for they are always a source of failure. The only exceptions to this 
rule are perhaps a certain few cases where the enamel is not subjected to 
severe or direct strain ; as, for instance, in proximal cavities in front teeth 
in which, for cosmetic reasons, it seems advisable to conserve the enamel 
of a thin labial wall. The brittle character of the enamel, however, ren- 
ders it liable to be fractured whenever direct strain comes upon it, unless 
it is supported by something to counteract the strain. Its most natural 
support is the dentin, but occasionally in such instances as those just 
mentioned artificial support in the form of oxyphosphate cement may be 
given to it before the introduction of a gold filling. The student is warned, 
however, against attempting to apply this method of support in any other 
class of cases, as failure is more than likely to follow all such attempts 
from the severe strain brought upon the teeth during mastication. 

Dr. Black, in his "Investigation of the Physical Character of the 
Human Teeth, etc.," demonstrated in the most positive manner, by elabo- 
rate and painstaking experiments, that many of the popular theories 
among dental practitioners in reference to the density of tooth-structure 
in early adult and advanced life, and their relative strength at these 
periods, were in many respects fallacious. The following table gives a 
general summary of the result of his investigations upon these points : 



236 



OPERATIVE DENTISTRY. 

General Summary of Results. 



No. of 

Cases. 



Average 
Age. 



No. of 
Tee tli. 



Specific 
Gravity. 



Per 
cent, of 
Water. 



Per 

cent, of 
Lime 
Salts. 



Per 

cent, of 
Organic 
Matter. 



Average for total number of 
teeth 

The highest percentage 

The lowest percentage 

Greatest variation 

Average for persons under 15 

years old 

Average for persons 15 years old 

and under 20 

Average for persons 20 years old 

and under 25 

Average for persons 25 years old 

and under 30 

Average for persons 80 years old 

and under 40 

Average for persons 40 years old 

and under 50 

Average for persons 50 years old 

and under 60 

Average for persons 60 years old 

and over 

Average for males 20 years old 

and under 30 

Average for females 20 years old 

and under 30 

Average for males 30 years old 

and under 40 

Average for females 30 years old 

and under 40 

Average for males 40 years old 

and under 50 

Average for females 40 years old 

and under 50 

Increase due to age 

Decrease due to age 

Average for persons who lost 
their teeth from diseases of the 
peridental membranes 

Average for cases in which the 
teeth are classed as bad. 

Average for cases in which the 
teeth are classed as good 

Average for cases in which the 
teeth are classed as fair 

Average for perfect teeth 

Average for carious teeth 



2.092 
2.133 
2.036 
0.097 



11.06 
13.56 
9.32 
4.24 



63.5-1 
65.75 
61.08 
4.67 



11.00 
17.00 
21.55 
25.93 
33.00 
42.66 
53.00 



2.066 
2.080 
2.081 
2.086 
2.092 
2.094 
2.105 
2.019 



11.89 
11.46 
11.47 
11.27 
10.84 
10.91 
10.85 
10.66 



62.26 
63.18 
63.43 
63.44 

63.83 
64.56 



2.0S2 
2.083 
2.090 
2.094 



63.30 
63.51 
63.35 
63.48 
63.54 
63.92 



2.30 



28.00 
33.53 

36.19 

36.26 
31.50 



2.087 
2.090 

2.090 

2.095 
2.091 



11.25 

11.16 

10.95 
11.03 
11.06 



63.33 
63.53 

63.56 

63.59 

62.50 



25.36 
27.59 
23.26 
4.33 



25.92 
25.33 
25.23 
25.28 
25.66 
25.34 
25.29 
24.81 



25.49 
26.31 

25.48 

25.36 
25.36 



It has been generally believed that the teeth were very soft in child- 
hood and increased in density to old age ; that the teeth increased in 
strength from childhood to middle life ; that the strength of the teeth de- 
pended upon their density, and that the density of the teeth, or the per- 
centage of lime-salts which the tissues contained, was a controlling factor 
in the liability to caries. 

From the facts developed in this investigation the following conclu- 
sions are drawn by Dr. Black : 

(1) ' ' The teeth are strongest in youth and early adult age, diminishing 
somewhat in strength with advancing age." 

This was ascertained first for the dentin by applying the stress to cubes 
eight-hundredths of an inch square cut from the dentin of permanent 



PREPARATION OF CAVITIES. 



237 



Exhibit of Elasticity and Crushing Stresses of Blocks of Dentin Eight-Hundredths 
of an Inch Square. Arranged according to the Age of Persons. 





Case. 


Age. 


Tooth. 


Carious 

or 
Perfect 


Pulp 
Living 

or 
Dead. 


Specific 
Gravity. 


Per 

cent, of 
Lime- 
Salts. 


1§ 


is 

cS"- 1 

SI 


is 


"3 . 




246 


9 


IV 


c 


1 


2.069 


62.83 


1.5 


3 


285 






212 


10 


VI 


c 


1 


2.064 


61.77 


3 


5 


235 






211 


11 


/F 


c 


d 


2.061 




2 


4 


247 






207 


12 


/F 


c 


1 


2.073 


62.40 


2 


3 


240 






245 


12 


/F 


c 


1 


2.068 


62.42 


1.5 


3 


235 


248 




188 


16 


F/ 


c 


1 


2.067 


61.71 


2 


4 


275 






218 


16 


6/ 


c 


d 


2.078 


62.83 


2 


3.5 


225 






244 


16 


/F 


c 


d 


2.080 


63.59 


2 


5 


210 






208 


18 


/F 


c 


1 


2.080 


63.65 


3 


5 


210 


230 




210 


22 


H7 


c 


1 


2.054 




1.5 


3.5 


302.5 






222 


22 


M 


c 


1 


2.098 


63.80 


2.5 


4.5 


235 






229 


22 


/5 


c 


1 


2.105 




3 


4.5 


245 






221 


23 


/F 


c 


1 


1.100 


64.39 


2 


3 


270 






223 


23 


6/ 


c 


1 


2.085 


63.32 


3 


5 


220 










/6 


c 


d 


2.067 


63.27 


2 


4 


235 










M 


c 


1 


2.079 


62.72 


2 


4 


270 






228% 


24 


/H 


c 


1 


2.068 




2.5 


4.5 


245 






173 


25 


n 

IS 
/G 


c 

c 


1 
1 
1 


2.110 
2.131 
2.095 








200 
216 
275 






213 


25 


F/ 


c 


1 


2.080 


63.01 


2" 


4" 


280 






216 


26 


/6 


c 


1 


2.099 


63.31 


2 




235 






200 


27 


H/ 


p 


1 


2.098 


61.77 


2 


4 


270 






247 


27 


6/ 




1 


2.104 


64.79 


1 


2.5 


285 






200 


28 


/8 


c 


1 


2.070 


63.19 


1.5 


3 


300 










8/ 


c 


d 


2.043 


62.01 


2 


4 


260 


260 




194 


30 


IF 


c 


d 


2.101 


63.71 


2 


4 


250 






215 


31 


(E 


c 


1 


2.126 




2.5 


4 


245 










/F 


c 


d 


2.117 




2.5 


4.5 


230 






196 


35 


6/ 


c 


1 


2.096 


04. ii' 


2 


4 


250 






198 


35 


8/ 


c 


1 


2.123 


64.77 


2 


4 


255 






203 


35 


8/ 


c 


d 


2.082 


63.31 


2 


4 


225 






230 


35 


/5 


p 


1 


2.102 


63.39 


3 


4.5 


265 










3/ 


p 


1 


2.074 


63.27 


2.5 


4.5 


245 










n 


p 


1 


2.097 


64.63 


2 


4 


252 










7/ 


p 


1 


2.087 


63.91 


3 


5 


250 






217 


36 


7/ 


c 


1 


2.108 


C3.77 


5 


8 


200 


242 




202 


40 


IV 


p 


1 


2.072 


63.99 


2 


4 


225 






228 


42 


/H 


c 


1 


2.101 




3 


5 


262 










/E 


c 


d 


2.108 


64.06 


3 


7 


200 






192 


44 


4/ 


p 


1 


2.096 


63.97 


2 


4 


240 










/4 


c 


1 


2.108 


63.74 


3 


6 


250 










/6 


c 


1 


2.068 


62.05 


2.5 


5 


250 










7/ 


p 


1 


2.111 


64.51 


2 


4 


265 










/7 


p 


1 


2.098 


64.26 


2.5 


5 


220 






175 


45 


Id 

IS 
8/ 


c 
c 

p 


d 
d 

1 


2.078 
2.099 
2.085 








183 
178 
225 






231 


47 


VI 


c 


d 


2.103 


64.13 


3 


4.5 


200 






227 


49 


G/ 


c 


1 


2.105 


64.53 


3 


5 


220 


224 




193 


50 


6/ 


p 


1 


2.109 


64.66 


2.5 


5 


220 






174 


51 


8/ 


p 


1 


2.123 








207 






250 


51 


/6 


c 


1 


2.103 


64.29 


1.5 


3" 


235 






209 


58 


7/ 


p 


1 


2.100 


63.61 


2 


4 


215 


219 




214 


60 


IV 


c 


d 


2.106 


64.68 


2 


4 


230 






233 


60 


13 


p 


1 


2.091 


63.78 


2 


4 


200 










3/ 


p 


1 


2.095 


63.84 


2 


4 


215 










/4 


p 


i 


2.088 


62.95 


1.5 


3 


210 










4; 


p 


1 


2.096 


63.22 


2.5 


4.5 


220 










5/ 


p 


1 


2.059 


62.25 


2.5 


5 


195 










6/ 


p 


1 


2.086 


63.59 


2 


4 


200 










/.6 


p 


d 


2.093 


63.62 


1.5 


3 


260 










11 


p 


1 


2.109 


63.94 


2.5 


4.5 


250 










7/ 


p 


1 


2.097 


63.59 


1.5 


3 


250 






234 


60 


6/ 


p 


1 


2.122 


64.57 


1 


2.5 


290 






195 


61 


3/ 


p 


1 


2.118 


63.07 


2 


5 


260 










8/ 


p 


1 


2.112 


64.16 


2 


4 


235 










/8 


c 


d 


2.113 


64.16 


3 


6 


225 






226 


63 


/6 


c 


1 


2.104 


68.24 


8 


1.2 


185 






232 


65 


/8 


c 


1 


2.119 


04.10 


2 


3 


215 


227 


Average . . . 
















2.09 


4.3 


23S 




Number . . . 


44 




70 



















238 OPERATIVE DENTISTRY. 

teeth of all ages. The instrument for applying and recording the amount 
of stress used was especially made for this purpose. 

The specific gravity of the dentin in all the specimens was ascertained, 
and the percentage of lime-salts also was obtained in nearly all, as well as 
the age of the individual furnishing the specimen, the particular tooth, 
whether sound or carious, the condition of the pulp, whether vital or dead, 
and all made a matter of record, together with the elasticity of the dentin 
under stress at one hundred pounds to the square inch, at one hundred 
and fifty pounds, and the number of pounds at which the block of dentin 
crushed. 

A reference to the foregoing table of results will show the figures in 
detail. It appears from this exhibit that the average crushing stress of 
dentin between the ages of nine and twelve inclusive is two hundred and 
forty-eight pounds to the square inch ; between the ages of sixteen and 
eighteen inclusive, two hundred and thirty pounds ; between twenty-two 
and twenty-eight years of age, two hundred and sixty pounds ; between 
thirty and thirty-six years, two hundred and forty-two pounds ; between 
forty and forty-nine years, two hundred and twenty-four pounds ; between 
fifty and fifty-eight years, two hundred and nineteen pounds ; between 
sixty and sixty-five years, two hundred and twenty-seven pounds. The 
total average crushing stress was two hundred and thirty-eight pounds. 

In the table of l ' General Summary of Eesults' ' the average specific 
gravity of the teeth at eleven years was found to be 2.066, while the 
average at the age of sixty-three was 2.019, giving a difference of forty- 
seven-thousandths of a volume. 

The increase in the amount of lime-salts follows the same rule. Be- 
ginning with 62.26 per cent, as the average at eleven years of age, it is 
increased to 64.56 per cent, as the average at sixty-three years of age, an 
increase of 2.3 per cent. 

The enamel was found to be very frail, the enamel-rods chipping off 
under very slight stress. 

The blocks of enamel, which were the same size as the blocks of 
dentin, except that they were only four-hundredths thick (8 x 8 x 4), 
crushed under a stress of from thirty to seventy-five pounds to the 
square inch. 

This emphasizes the need of the greatest care being exercised in the 
preparation of the enamel margins to prevent their being injured after 
the filling has been inserted, by the stress of mastication. 

A study of the force of the jaws in mastication, which was first under- 
taken by Patrick and Dennis in 1893, developed the interesting fact that 
the stress exerted by the jaws in biting was very much greater than had 
been supposed. 

Black discovered that there was a very great difference in the stress 
exerted by different individuals, ranging in adults from one hundred and 
twenty to two hundred and seventy pounds and more. 

The following table gives the results of tests of fifty persons, ranging 
from four and one-half years of age to forty-five years : 



PREPARATION OF CAVITIES. 



239 



Gnathodynamometer Records. 



Occupation. 



Farmer 

Railroad passenger agent 

Railroad man 

Butcher 

Bookkeeper 

Miss, seven years old 

Servant-girl 

Teacher 

Dentist 

Grocer 

School -girl 

Laborer 

Physician 

Salesman 

Music-teacher 

School-girl 

Temporary molars 

Merchant 

Music teacher, on bridge 

On temporary molars 

Farmer 

Watchman 

Artist 

School-girl 

Chinese laundryman 

Grocer 

Athlete 

Butcher 

Lawyer 

Blacksmith 

Machinist 

Banker 

Bank clerk 

Dentist 

Grocer 

Farmer 

Temporary molars 

School-girl 

Physician 

Printer 

School -girl 

Student 

School -girl 

Physician 

Dentist 

Athlete 



Sex. 


Age. 


Height. 


Weight. 


Incisors. 


Bicus- 
pids. 


M 


25 


5-5 


127 


55 




M 




6 


203 


100 




M 




5-7 


128 






M 




5-9 


155 


160 




F 




5-3 


112 


40 




F 




5-5 


90 


85 




F 


7 


3-4 


56 


30 




F 


23 


5-2 


98 


45 




M 


45 


5-2 


140 


100 




M 


38 


5-6 


165 


175 




F 


30 


5-2 


130 






M 


28 


5-9 


140 


85 




F 


18 


5-2 


117 


75 


135 


M 


40 


5-9 


190 


100 




M 


31 


5-6 


180 


75 




M 


22 


5-7 


140 


80 




F 


25 


5-6 


110 


05 




F 


18 


5-6 


110 


50 




F 


24 


5-4 


130 


90 




M 


8 










M 


30 


5-10 


140 


45 




F 


35 


5-5 


120 






M 


8 










M 


26 


6-3 


200 


60 




M 


25 


5-8 


150 


100 




F 


35 


5 


110 


45 




F 


19 


5-11 


123 


60 




F 


24 


5 


110 


45 




M 




5-4 


140 


50 




M 




5-10 


204 


130 




M 




6 


230 


70 




M 


30 


5-5 


176 


140 




M 




5-9 


164 


65 




M 


45 


5-8 


195 


45 




M 


40 


5-3 


130 


80 




M 


35 


6 


148 


30 




M 




5-5 


130 


60 




M 


35 


5-8 


220 


45 




M 




5-8 


150 


80 




M 




6 


170 


90 




M 
F 


4K 




40 
100 


70 




M 


35 


5-11 


205 






M 


32 


5-6 


105 






F 


19 


5-5 


120 






M 


18 


5-8 


130 


70 


130 


F 




5-4 


102 


50 




M 


32 


5-7 


135 




185 


M 


40 


5-5 


120 


60 




M 




5-7 


150 


120 





100 
140 
240 
155 
160 
150 
180 
130 
135 
120 

160 

65 
155 
145 

45 
145 
160 

65 
135 

60 
165 
170 
160 
165 
160 
140 
160 

70 

85 
160 
160 
190 

45 
120 



100 
120 



The application of these facts to the strength of the dental tissues, and 
to' the effect upon fillings and their anchorage, will result in more careful 
preparation of the enamel margins and more substantial anchorage of 
fillings. 

The instruments invented by Patrick and Dennis for measuring the 
strength of the jaws, and later perfected by Dr. Black, is known as the 
' l Gnathodynamometer. ' ' 

(2) " Teeth that have lost their pulps and have become discolored lose 
strength in a marked degree, apparently from a deterioration of the 
organic matrix." 

Tests were made of the strength of fifteen pulpless and discolored teeth 
from persons ranging from twenty-five to fifty years of age, all of which 
succumbed to stresses between one hundred and thirty to two hundred 
pounds. 

(3) ' ' Teeth that have become badly worn from mastication and in which 
the pulps had become so calcified as to cut off the nutrition of the crown 



240 OPERATIVE DENTISTRY. 

portion of the dentin, lose strength apparently from deterioration of the 
organic matrix." 

(4) ' ' Teeth of old people, and especially those in which much calcifi- 
cation of the pulp occurs, deteriorate in strength." 

(5) " There is no basis for the supposition that the teeth of children, 
under the age of twelve years, are too soft to receive metallic fillings." 

(6) " Differences in density, or in the percentage of lime-salts in the 
teeth, is not the controlling factor in the strength of the teeth nor of their 
hardness, this seeming to depend upon the condition of the organic 
matrix." 

(7) "Differences in the strength of the teeth have no influence as to 
their liability to caries. Differences in density or in the percentage of 
lime-salts in the teeth have no influence as to their liability to caries." 

(8) " The active causes of caries is a thing apart from the teeth them- 
selves, acting upon them from without, and from a consideration of the 
facts thus far developed, the logical inference is that the cause of the differ- 
ences in the liability of individuals to caries of the teeth is something in 
the constitution, operating through the oral fluids, and acting upon the exciting 
causes of caries, hindering or intensifying its effects.'' 1 

(9) ' ' Caries of the teeth is not dependent upon any condition of the 
tissues of the teeth, but on conditions of their environment." 

(10) "Imperfections of the teeth, such as pits, fissures, rough or un- 
even surfaces, and bad forms of interproximate contact, are causes of 
caries only in the sense of giving greater opportunity for the action of the causes 
that induce caries." 

(11) "The objects to be attained in filling teeth are the perfect exclu- 
sion of the causes of caries from the tissues by sealing the cavity, and 
securing such form as will prevent lodgement of debris about the margins of the 
filling, and thus prevent the further action of the causes of caries. ' ' 

(12) " There is no basis for the supposition that some teeth are too soft 
or too poorly calcified to bear filling with gold or other metal in use for that 
purpose, since all are found to be abundantly strong." 

(13) "There is no basis for the selection and adaptation of filling- 
materials to soft teeth, hard teeth, frail teeth (in structure), or poorly 
calcined teeth. What basis there may be in the conditions surrounding 
the teeth for the selection and adaptation of filling-materials must be left 
to future development to discover." 

(14) "With our present knowledge the only basis for the selection and 
adaptation of filling-materials to classes of cases is the individual opera- 
tor's judgment, as to which he can so manipulate as to make the most per- 
fect filling, considering the circumstances (environment), his own skill, and 
the durability of materials." 

(15) "There is no basis for the supposition that calcic inflammation 
of the peridental membrane, or phagedenic pericementitis (so-called 
pyorrhoea), attacks persons who have dense teeth in preference to those 
whose teeth are less dense." 

(16) ' ' There is no basis for the treatment of pregnant women medici- 
nally with the view of furnishing lime-salts to prevent the softening of 



PREPARATION OF CAVITIES. 



241 




their teeth, or with the view of producing better calcined teeth in their 
offspring." 

PREPARATION FOR OPENING THE CAVITY. 

Many operators are in the habit of applying the rubber dam in all 
cases before commencing the operation of cavity preparation. The writer 
prefers to clear the cavity of the thin 

overhanging enamel edges, food debris, Fig. 367. 

and the most softened portions of the 
dentin before applying the dam, as 
this gives opportunity for frequent use 
of the syringe (Fig. 367) and warm water-syringe (reduced). 

water charged with antiseptics or 

alkaline solutions, which often very materially adds to the comfort of the 
patient, and not a little to the sense of cleanliness, as well as relieving the 
patient for a portion of the time of what is to many the disagreeable pres- 
ence of the rubber dam. Absolute dryness, however, is always necessary 
in the final preparation of the cavity, as the exclusion of moisture makes 
it more easy to locate slightly discolored and decalcified dentin. 

The selection of the instruments with which to open the orifice of a 
cavity will depend upon its location, size, and accessibility. 

Cavities located upon the morsal, lingual, or labial surfaces of the tooth 
crown are easily accessible, but those upon the approximal surfaces do not 
give ready access until after space has been gained by some of the methods 
of temporary separation described in the preceding chapter. 

Small cavities located upon any exposed surface can best be opened by 
the use of some form of small engine bur. 

The forms of burs best adapted to the opening of small accessible cavities 
are the pointed fissure, dentate, round, and inverted cone. Figs. 368 and 



Fig. 368. 





Fissure, pointed. Dentate. 

369 illustrate these forms. The pointed fissure bur is by far the most service- 
able instrument for opening very small cavities or fissures. Its shape facili- 
tates its entrance into the cavity, while it also more readily follows a fissure. 
Spear-pointed drills are not so serviceable for this purpose, on account 
of the fact that they are frequently broken by being caught in the irregu- 
larities of the cavities or in the fissures. 

16 



242 



OPERATIVE DENTISTRY 



In the larger cavities enamel-chisels are much more useful for opening 
[he cavity, and are less painful to the patient. In using enamel-chisels 




Inverted cone. 



advantage is taken of the natural lines of cleavage of the enamel, as shown 



Fig. 370. 




Diagram illustrating cleavage of the enamel and lines upon which the margin should be cut prepara- 
tory to filling, a, chip thrown off by the chisel ; 5, position of the chisel in splitting off overhanging 
margins ; c, c, correct lines upon which to cut the margins preparatory to filling ; d, d, incorrect lines for 
the preparation of the margins for filling ; /, cavity in the dentin. (After Black.) 

and effectually cut away. The selection of the form and size of the chisel 
should depend upon the size, location, and the accessibility of the cavity. 

Fig. 371. 





A set of three-edged chisels recently invented by E. Parmley Brown 
(Fig. 371) are most admirable for opening cavities, enlarging fissures, cut- 



PREPARATION OF CAVITIES. 



243 



ting away overhanging edges of enamel, and trimming the cervical margins 
of cavities. Other forms of chisels are shown in Fig. 372. 

Fig. 372. 




Chisels may be used either with hand-pressure or by the driving force 
of the mallet. The sharp, quick stroke of the mallet is the most effectual 
force to use in cleaving the unsupported edges of the enamel, while there is 
much less danger of the instrument slipping and injuring the soft tissues 
of the mouth or the pulp than when hand-pressure is used. 

The chisel should be held between the thumb and first two fingers of 
the right hand, as a pen is held, while the ring and fourth fingers rest 
upon an adjacent tooth or some convenient part of the face or chin, to 
guard against slipping. This position of the hand in holding the chisel 
applies equally to the engine hand-piece, excavators, mallet pluggers, and 
other small-handled instruments. 

In opening cavities upon the approximal surfaces which have been 
brought to view by separating the teeth, and which are superficial and of 
limited extent, small round or inverted cone-shaped burs will be found 
most useful ; while in cavities of larger size one of the smaller sizes of the 
Parmley Brown chisels, which cut upon the sides as well as the point, will 
be found advantageous in cleaving the thin edges of the enamel. They 
are also especially useful in preparing approximal cavities in the incisors 
and cuspids, and for trimming enamel margins. 

Time will be saved in the after-procedure of removing the decay if in 



244 OPERATIVE DENTISTRY. 

the operation of opening the cavity the overhanging enamel has been at 
once cut away until sound dentin has been reached. 

The unnecessary sacrifice of enamel-tissue is, however, to be avoided, 
but nothing is gained by temporizing. 

In the heroic use of the enamel- chisel iu the first step in the operation 
of cavity preparation lies the secret of rapid excavation, while much pain 
and fatigue will be saved to the patient and better results will follow than 
by timid, half-hearted measures. 

Removing the Decay. — In removing the softened decalcified dentin 
from a carious cavity care should be exercised to inflict as little pain as 
possible. Its thorough removal, however, is absolutely necessary to the 
success of the after-treatment. The method of operation to be adopted in 
removing the carious dentin will depend upon the character and con- 
sistency of the disorganized material to be excavated. These characteris- 
tics of the decalcified dentin may be divided into three varieties : one is 
white and of chalky consistency, another is light brown, semi- elastic, or leathery, 
and the last dark brown or black and quite hard. 

In the first variety, which is characteristic of the most rapid form of 
caries, the dentin is often exquisitely sensitive. 

Spoon-bladed or round-bladed excavators will be found most useful in 
removing the decalcified tissue, and the risk of exposing the pulp will be 
much less than if engine-burs are used, from the fact that the decalcifica- 
tion of the tissue has many times progressed almost to the pulp before the 
cavity has been discovered. 

In the second variety, having a semi-elastic, leathery consistency, exca- 
vators having round or spoon blades (Fig 373) will also be found most 
serviceable in removing the carious dentin. 

This character of decay is most often seen in the teeth of young people, 
and is not infrequently very sensitive. In all operations for removing 
carious dentin, the fact should be kept constantly in mind that the most 
sensitive portion of a tooth is at the j>eriphery of the dentin, immediately 
beneath the enamel, and that the dentinal fibrillse, in advancing from the 
pulp to the periphery of the dentin, have a direction which is perpendicu- 
lar to the surface of the tooth. Much pain may, therefore, be saved the 
patient if at the outset of the operation a few bold sweeps of the excavator 
are made around the circumference of the cavity immediately beneath the 
enamel, and that all subsequent cuts of the excavator, so far as possible, 
follow a line from the centre of the tooth to the periphery, rather than 
from the periphery to the centre. In the leathery form of carious dentin, 
many operators advise removing the dentin layer by layer, beginning at 
the periphery of the cavity and gradually lifting them out until all of the 
material of this character has been removed. 

The excavator should be kept sharp, and each cut of the instrument 
should be decided. Scraping of the sensitive dentin is much more painful 
than a firm, decided cut that accomplishes something. The greatest kind- 
ness that can be shown a patient under these circumstances is to be thorough, 
but at the same time rapid ; and these conditions are not inconsistent to the 
mind of the bold but conscientious operator. 






PREPARATION OF CAVITIES, 



245 



Thorough excavation of a cavity comprehends the removal of all dis- 
organized and infected dentin. This may not always be done with safety 

Fig. 373. 




to the pulp, but, as a general rule, this procedure should be carried out. 
There is only one way to determine when all infected tissue has been re- 
moved, and that is by the density of the tissue. All soft, leathery dentin is 



246 OPERATIVE DENTISTRY. 

infected, but Miller has proved that all partially decalcified dentin is not 
infected, as the process of decalcification is always in advance of the 
presence of the micro-organisms in the tubuli. 

The meaning of the term thorough excavation would necessarily, then, 
depend somewhat upon the judgment and experience of the operator as 
to whether all infected tissue had or had not been removed. The only 
safe method, except in the case of nearly exposed pulps, is to excavate 
until sound, hard dentin has been reached. 

Partially decalcified dentin may be allowed to remain in the bottom of 
the cavity, as recalcification will usually take place in this tissue, and 
also for the reason that it will protect the pulp from thermal shock. 
Thorough disinfection should, however, precede the introduction of 
the filling. For this purpose mercuric bichloride 1 to 500, carbolic acid 
ninety-five per cent., oil of cloves, oil of peppermint, or listerin, etc., may 
be used. 

In the operation of removing the decayed dentin the surfaces of the 
cavity should be left as smooth as possible. Undercuts, grooves, or gen- 
eral unevenness of the walls of the cavity should be avoided, except those 
which are made for the definite purpose of retention, as the filling-material 
is more readily adapted to smooth walls. 

In the third, or dark, hard variety, the carious process is very slow and 
sometimes becomes arrested or self-limited. In arrested caries the dentin 
is always of a darker color than ordinary dentin, and might be mistaken 
for caries but for its greater hardness. It should not be removed except 
from the margins of the cavity, where its color would be objectionable 
and prevent a clear, clean appearance of the finished operation. 

The dentin in the dark variety of caries is not more sensitive usually 
than dentin in its normal state. Cavities of this character rarely penetrate 
to a depth involving or jeopardizing the integrity of the pulp • conse- 
quently they are the most favorable cases for restoration by plugging with 
gold. 

Retentive Shaping. — After the cavity has been cleared of all disor- 
ganized and infected tissue, the next step in the operation of cavity prepa- 
ration is to give it such shape that the filling, after it has been inserted, 
cannot be mechanically dislodged ; while at the same time the retentive 
shaping must not be carried so far as to weaken the walls or to endanger 
the pulp. These points cannot be too strongly emphasized, for upon their 
proper appreciation and practical application will largely depend the 
future success or failure of the completed operation. Upon a correct 
application of the laws of mechanics to the art of filling teeth will de- 
pend the retention of the filling after it has been inserted. The shape of 
the cavity must therefore be such that the completed filling cannot be dis- 
lodged by mechanical force without fracturing the walls of the cavity or 
cutting the filling into pieces. 

It is obvious, however, that a single method of securing retention will 
not suffice for all cavities. Various methods must therefore be employed, 
and their individual or combined application must depend upon the 
general form and character of the cavity to be filled ; but, as a general 



PREPARATION OF CAVITIES. 247 

rule, it may be stated that the cavity should be slightly larger at the 
bottom than at the orifice. 

In small cavities, however, in which the depth is equal to or greater 
than the diameter, the walls may be left jmrallel to each other, as the 
lateral walls will contain a sufficient number of uneven points to secure 
retention of the filling. 

In shaping the cavity, care should be used to leave the walls as free 
from angles as possible, as there is greater difficulty in adapting the filling 
to such surfaces. To this end the excavators used should be of the spoon 
or rounded form and the burs either round or oval. 

The reverse of this is true in cavities of larger size, where the diameter 
of the cavity is greater than its dearth. Guilford formulates two rules to 
govern these conditions, as follows : 

"1. When the depth of the cavity is greater than the diameter of the 
orifice parallel lateral walls will prove retentive. 

"2. When the diameter of the orifice is greater than the depth of the 
cavity the latter will have to be somewhat enlarged internally to retain 
the filling." 

The first class of cavities are usually found occurring in the pits, upon 
the lingual surfaces of the superior incisors, the morsal surfaces of the 
superior and inferior bicuspids and molars, the lingual surfaces of the 
superior molars, and the buccal surfaces of the inferior molars. 

The second class of cavities are found in nearly all locations upon the 
various surfaces of the crowns. 

In some cases the cavities formed by decay will be found to possess a 
retentive form after the carious dentin has been removed, but, as a rule, 
retentive shaping will be required, making it necessary to cut away more 
or less sound dentin. Care should be exercised, however., not to carry this part 
of the operation too far, as the walls of the cavity would thereby be weak- 
ened, or the pulp encroached upon to such an extent as to cause after- 
trouble. The tendency of the student and the young practitioner is to 
carry retentive shaping too far. 

Deep undercuts, grooves, or pits are not necessary to retain a filling. 
These means of retention are just as effective from the mechanic stand- 
point if they are of moderate depth as though they were much deeper, 
while the dangers from fractured walls or pulp irritation are greatly 
lessened. 

Approximal cavities in bicuspids and molars should be so shaped as to 
secure as broad and flat a foundation as possible at the cervical wall for 
the support of the filling. The laws of engineering require that the base 
or foundation of a structure shall be equal to, or greater, in surface area 
than the structure to be reared upon it. This applies with as much force 
to filling teeth as to building suspension bridges, twenty-story buildings, 
or Eiffel towers. The greater the load to be carried, the broader and 
stronger must be the foundations upon which the load is to rest. 

If this fact is appreciated and applied to the preparation of this class 
of cavities, there will be many less failures in approximal fillings in bicus- 
pids and molars- 



248 



OPERATIVE DENTISTRY. 



13 



Fig, 374. 
I 




scribed 



Retentive forms may be given to cavities by making the bottom of the 
cavity slightly larger than the orifice ; by the formation of shallow grooves 

at opposite points at the base of the 
cavity ; by pits drilled at opposite 
points ; or by a combination of these 
means of retention. In compound 
cavities — those involving two or 
more surfaces — retention is often 
strengthened by giving a dove-tail 
form to one portion of the cavity. 
Occasionally, on account of the loss 
of tissue, retention cannot be ob- 
tained by any of the means just de- 
it then becomes necessary to secure the filling by 
setting one or more screw-posts. 

These posts may be set upon opposite sides of the cavity, 
with an inclination towards each other, or a single post may 
conserve the purpose of retention. Fig. 374 shows a set of 
instruments for this purpose. In setting these posts, a spear- 
pointed drill is used to make the hole which is to receive the 
post ; this is followed by a tap, cut with the same thread as 
that upon the gold wire used for the post, and of the same 
size. A post of suitable length is then cut from the wire and 
set in the hole prepared for it. 

It is never wise to set a post or make a groove or pit in the 
incisal or morsal surfaces of the tooth or very near the enamel, 
as their presence tends to weaken this part of the tooth and 
makes fracture of the walls very liable to occur under the 
stress of mastication! 

Forming Cavity Margins. — This part of the operation is also an ex- 
ceedingly important one, from the fact that without a proper forming of 
the cavity margins perfect adaptation of the filling-material to the enamel 
borders is an impossibility, and consequently leakage soon takes place at 
these defective points and the operation becomes a failure. Another im- 
portant point in the process of shaping the margins of the cavity is to cut 
away all thin and weakened enamel, for if it is allowed to remain fracture 
is liable to occur either in adapting the filling-material to it or in the stress 
incident to mastication. 

In the final preparation of cavity margins, the best results will be 
obtained by slightly bevelling these borders by cutting the enamel-rods in 
an oblique direction, as shown in Fig. 375, c, c. If the walls are cut per- 
pendicular with the wall of the cavity, as in d, d, certain of the enamel- 
rods would have no support of dentin, and consequently they would be 
more liable to fracture from cleavage than if cut away as shown in c, c. 

In cavities occurring upon concave surfaces, as, for instance, in the 
fissures upon the morsal surfaces of bicuspids and molars, the lines of 
enamel cleavage would have an inward direction, the reverse of that shown 
at d. The bevel, therefore, given to the enamel margins in this class of 



5 



PREPARATION OF CAVITIES. 



249 



cavities should— in order that no enamel-rods be left without proper sup- 
port of the dentin — be a little greater than that given to the margins of 
cavities occurring upon convex surfaces. 

Fig. 375. 




The instruments which are best suited to the purpose of preparing the 
enamel margins are chisels, broad-face hoe excavators, barrel-shaped file- 
cut burs, and Arkansas stones. The margins should be left as smooth as 
possible, but in the use of the burs and stones care must be exercised not 
to round the edges of the margins, as this would leave a feather-edge to 
the filling after it was finished, and would be liable to peel up or become 
rough, thus spoiling the appearance of the marginal contact and opening 
the way for the establishment of secondary caries. 



CHAPTER XVII. 

TREATMENT OF CARIES BY OBTURATION, OR FILLING. 

Definition. — Obturation (from the Latin obturare, to stop up), the 
act of stopping a hole or covering an opening. 

" Obturation of the Teeth. — The filling of cavities in the teeth pro- 
duced by caries with a substance capable of resisting the destructive 
action of fluids or the force of mastication." 

The operation of removing disorganized substances from a carious tooth 
and mechanically filling, stopping, or plugging the cavity should, strictly 
speaking, be termed an obturation, and the inserted filling an obturator. 

Custom, however, sanctions the use of the term filling, etc., as applied 
to the closing of a cavity in a tooth, and generally restricts the use of the 
term obturation to the mechanical procedure of stopping or covering an 
opening in other tissues caused by developmental defects, disease, acci- 
dent, or surgical operation, and of obturator to the instrument or appli- 
ance which closes or stops the opening. 

The introduction of a filling-material into a prepared cavity in a tooth 
is a purely mechanical procedure, but one which, nevertheless, with certain 
materials, like gold-foil, calls for a high degree of mechanical ability and 
manipulative skill. Upon the possession of these qualifications will de- 
pend, in no small degree, the success or failure in saving the teeth by the 
operation of filling. It matters not how perfectly the cavity may have 
been prepared, if the completed filling is faulty in its adaptation to the walls 
of the cavity and the enamel margins, — in other words, does not hermetically 
seal the cavity, — or the margins are not perfectly finished, or the surface is 
rough or not properly contoured, the final result will be failure. 

The main objects in introducing a filling into a prepared cavity are to 
arrest the further progress of the carious process and to restore the tooth 
to its original form and usefulness. 

The consideration of the ways and means by which these results may 
be obtained must comprehend, — 

(a) The age of the individual ; the character of the teeth ; the condi- 
tion of the health, and the local environment ; also, 

(&) The nature and physical characteristics of the substances used as 
filling-materials. 

(c) Their capabilities of perfect adaptation to the walls of the cavity 
and the restoration of contour. 

(d ) Their conductivity and therapeutic action upon tooth-structure. 

(e) Their resistance to chemical action and mechanical abrasions ; and, 

(/) Their harmony of color with tooth-tissue. 

In the selection of the material with which to successfully fill a tooth 
an experienced judgment is required. This judgment in any given case 
must be based upon a full knowledge and appreciation of all the condi- 
tions presented by the individual to be operated upon, as well as the 
250 



TREATMENT OF CARIES BY OBTURATION, OR FILLING. 251 

nature, physical characteristics, and adaptability of each of the various 
materials that are generally used for this purpose. In a wise selection of 
the material to be used in each individual case lies one of the most im- 
portant elements in the conservation of decayed teeth. 

The dentist who fails to appreciate this fact will fall far short of render- 
ing the best possible service to his patients. 

FILLING-MATERIALS AND THEIR INTRODUCTION. 

The materials which are used for filling teeth are divided into two 
general classes, — viz., non-plastics and plastics. 

The non-plastics include all of the various forms of gold-foils, sponge or 
crystal gold, platinum gold-foil, and tin-foil. 

The plastics are amalgams, gutta-percha, and the various basic oxide 
cements. 

The ideal filling-material, like the u fountain of life," still lies within the 
realm of the undiscovered. No substance or combination of substances 
yet discovered possesses all of the features and characteristics necessary 
to fulfil the requirements of the ideal material for filling teeth. Such a 
filling must be indestructible in the fluids of the mouth, and not suscep- 
tible to chemical change in the presence of substances which enter the 
mouth as aliment or as medicinal remedies ; it must be easy of adaptation 
and capable of making a moisture-tight plug ; it must be so dense in 
structure as to retain its form and resist the abrasion of mastication ; capa- 
ble of being colored to match any shade of the natural teeth, and polished 
or glazed to imitate the enamel ; it must be a non- irritant and a non-con- 
ductor of thermal changes ; incapable of shrinkage or of staining the 
tooth-structure, and possessed of such adhesive and cohesive qualities as 
will retain it in any imaginable location and permit of the most elaborate 
contouring ; and, finally, it should possess such therapeutic properties as to 
make it preservative of tooth-structure. 

NON-PLASTIC MATERIALS. 

Gold. — Of all the materials that have thus far been used for filling 
carious cavities in the human teeth none possess in so high a degree so 
many of the desiderata of a perfect filling-material as gold, and yet this 
material falls far short of the ideal. 

Gold, nevertheless, by reason of its peculiar physical properties, occu- 
pies the first place among the materials which are used for this purpose, 
and experience teaches that after all the constitutional and local conditions 
and environment are considered, gold in the majority of instances is the 
most reliable material with which to preserve the teeth and restore portions 
lost by disease or accident that the dentist at the present time has at his 
command. 

PHYSICAL CHARACTERISTICS OF GOLD. 

Until the publication of the experiments of Dr. Black with regard to 
the "Physical Characteristics of Filling-Materials," very little was known 
of the behavior of gold and gold fillings under stress, such as would be 
exerted in the mastication of foods. 

In order to obtain data that would be reliable this investigator began 



252 



OPERATIVE DENTISTRY. 



his experiments with cast, hammered, and annealed gold of the same purity 
as that used by the dentist in filling teeth. The object of this was, first, 
to determine the amount of their strength and flow under stress of a given 
number of pounds, and then to compare these results with the strength of 
fillings made from the various preparations of gold- foil, etc., by the differ- 
ent methods of manipulation. 

Strength of Gold. — Blocks were prepared from bars of cast and ham- 
mered gold by turning in a lathe to an even size of one-hundred-and-forty- 
thousandths (fourteen one-hundredths) of an inch, and cutting pieces from 
the bar of the lengths which appear in the accompanying table, the ends 
being accurately squared. The specific gravity varied from 19.1 to 19.3. 

These were then subjected to compression in a dynamometer with a 
micrometer attachment. The pieces were placed with their squared ends 
between two parallel planes of steel, and the shortening of the blocks un- 
der a stress of two hundred pounds and three hundred pounds noted. 

The same sections of hammered gold were afterwards annealed and 
again subjected to the same stress, with the result of finding them much 
softer and much more yielding to the same pressure or stress. This is also 
shown in the table. 

Exhibit op the Strength op Cast, Hammered, and Annealed Gold under 
Compression. 



All results reduced to the basis of one-tenth 
inch cross-section. 



Case 1. Castgold, chemically pure. Specific gravity, 
19.2 ; diameter, 140. 



Average . 



Case 2. Cast gold, chemically pure. Specific gravity. 
19.25 ; diameter, 120. 



Case 3. Hammered gold, pure. Specific gravity, 
19.3 ; diameter, 140. 



The same pieces annealed. 



Case 4. Hammered gold. Specific gravity, 19.35 ; 
diameter of pieces, 115. 



The same blocks after annealing. 



10S.5 
107.5 
107.25 
100.0 



86.0 
101.0 
98.0 
83.0 



113.0 
121.0 



170.0 
121.0 
122.0 

Kio.o 



2X4.2 
339.7 
316.4 
274.5 



4011.0 
531.3 



492.0 
372.4 
380.0 

323.5 



Per cent, of shortening 
under a stress of 



200 lbs. 300 lbs. 350 lbs. 



4.24 
4.27 
3.91 
5.07 



1.79 

4.08 
2.62 
1.85 



0.33 
0.63 



6.34 
6.01 



0..HH 
0.40 
0.40 
0.53 



3.14 

6.75 



9.22 
12.16 
11.76 
11.70 



11.21 



8.06 
9.36 



1.35 

2.53 



12.70 
12.71 



2.94 
1.64 
1.64 

2.24 



12.93 
14 41 
14.16 
13.76 

13.38 



13.18 
17.34 
14.19 
13.03 



14.43 



2.72 
5.07 



16.23 
16.71 



10.00 
6.14 
3.68 
7.13 



6.73 



18.18 
19.36 
19.02 
19.22 

18.94 



TREATMENT OF CARIES BY OBTURATION, OR FILLING. 253 

Flow of Gold. — Dr. Black says, "As stress upon gold is increased 
to a point at which it begins to show signs of failure or yielding, it begins 
to flow or spread laterally. At first this flow is very slow, but as the stress 
is increased the flow occurs at a constantly increasing ratio." 

He found, however, that gold possessed the peculiarity of irregularity in 
its flow under pressure, the movement being rapid for a little time, then stop- 
ping, and again flowing. This was observed to invariably occur no matter 
how steadily the pressure was increased. 

It is generally recognized that gold is made stronger and denser by 
hammering and rolling. For the purpose of comparison with cohesive 
gold fillings, bars of gold were hammered as thoroughly as their size would 
permit. 

Hammered blocks of gold gave no evidence of flow at a stress of one 
hundred and fifty pounds. The average shortening under two hundred 
pounds' stress was 0.48 per cent.; at three hundred pounds', 1.98 per cent.; 
at three hundred and fifty pounds', 3.89 per cent. 

To test the strength and flow of gold fillings under stress, he caused to 
be made forty-eight fillings of the different preparations of cohesive and 
non-cohesive gold. Dr. Black made ten of these himself; the other thirty- 
eight being made by twelve different operators. These fillings were made 
in square and round cavities in a steel apparatus especially constructed for 
the purpose. The greater number were made in the square cavities, which 
measured one-third of an inch ; others in round cavities giving the same 
area in cross-section, but a considerable number were made in larger 
cavities. 

The only fillings that showed a specific gravity greater than that of 
hammered gold (19.3 or 19.4) were those made by Dr. Black. The first 
two were made with the intention of obtaining the highest specific gravity 
possible. In one a heavy mallet was used, and in the other a hammer, the 
force used being much greater than would he employed in filling a tooth. The 
specific gravity of the first was 19.38; of the second, 19.42. The third 
filling was malleted as would be usual in making a filling that would be 
exposed to unusual stress. The specific gravity of this filling was 19. 18. 
The specific gravity of the other fillings ranged from 18.61 to 10.7. The 
highest specific gravity of a cohesive gold filling was 18.61, and the lowest, 
10.7. The highest specific gravity of a non-cohesive gold filling was 18.2 ; 
the lowest, 16.9. 

Dr. Black found in making test fillings of purely non-cohesive gold, by 
the old method of wedging and hand-pressure, that a specific gravity of 
16.0 was about the best that could be done with a force that was admissible 
in filling teeth. These fillings went to pieces under very slight stress. 

This of course was hardly a fair test of the strength of non- cohesive 
fillings. Such fillings should be tested under conditions similar to those 
obtaining when they are supported by the walls of a tooth cavity. There 
is no doubt, however, that the strength of these fillings under stress is 
much below that of cohesive gold. 

Dr. Black recognizes this fact when he says, "Of course it must be 
understood that fillings made of purely non-cohesive gold depend upon 



254 OPERATIVE DENTISTRY. 

the support of the walls of the cavity for their strength, and tests of naked 
fillings are of little value, but the facts developed in this way may be in- 
structive to many in the placing of non-cohesive gold in the beginning of 
fillings in proximate cavities. It shows that it must be used in moderate 
amount, and so placed that it will be properly supported, or the strength 
of the filling will be notably impaired." 

Gold fillings are often required to carry a stress of from one hun- 
dred to one hundred and fifty pounds, and even more in persons with 
strong masticatory apparatus. Gold fillings, in order to successfully carry 
a stress of one hundred pounds upon an area one-tenth of an inch square, 
Dr. Black thinks, must have a density or specific gravity "of about 17.0, 
and be pretty well hardened by malleting." 

A filling one-tenth of an inch square, carrying a stress of one hundred 
pounds, should have a base equal to its size to rest upon. Dr. Black says, 
u If we obtain a flat gingival wall in a proximate cavity in a bicuspid tooth 
of only five-hundredths of an inch in breadth (one-twentieth of an inch) 
it will have to be full two-tenths of an inch long for the gold placed upon 
it to support one hundred pounds' stress, and to make it support one 
hundred and fifty pounds is out of the question." 

In approximal cavities in bicuspids and molars it has been a quite 
common practice to groove or undercut the buccal and lingual walls as a 
means of retention or anchorage. This method of preparing the cavity 
does not place these walls in a position to assist in carrying the load, but 
rather weakens them ; and if the seat of the filling is disturbed ever so 
slightly under stress, these walls are liable to be fractured, or the filling is 
drawn away from them, thus destroying the object for which it was inserted, 
by permitting the entrance of the agencies of decay and the ultimate de- 
struction of the filling. 

A better method is to prepare the cervical wall or base of the cavity 
as flat as possible, and the buccal and lingual wall without grooves or 
undercuts, and depend for support of a large part of the stress by cutting 
an additional seat in the morsal surface of the crown, and so shape this seat 
by dovetailing or other form as to give it good retentive powers. 

Platinum-gold fillings showed a slight advantage in strength over those 
made of pure gold at the same time and under the same circumstances, 
but the difference was not so marked as was anticipated. 

The difference found in the specific gravity of the fillings made for 
these experiments is explained by the difference in the consolidation of 
the gold, or, to state it in another way, was due to the difference in the 
number of air-spaces which the fillings contained. 

The flow of gold fillings, with a specific gravity of 17.0 and above, under 
the ordinary stress of mastication is so small as to be a matter of little 
consequence. 

Under a stress of one hundred and fifty pounds applied to hammered 
gold no evidence of flow was observed, while at two hundred pounds, a 
stress entirely out of the ordinary during mastication, it was only 0.48 per 
cent. 

The surprise, however, lies in the fact that fifty per cent, of the test 



TREATMENT OF CARIES BY OBTURATION, OR FILLING. 255 

fillings, as shown by the exhibit, fell below the indicated specific gravity 
of 17.0, a density necessary to carry a stress of one hundred pounds upon 
a one-tenth-inch area, and could not, therefore, be expected to carry the 
required stress, while twenty- nine per cent, were below 15.0 in specific 
gravity, and readily gave way under . a stress of one hundred and fifty 
pounds. 

THE PROPERTIES OF GOLD-FOIL. 

The properties of gold-foil which give it its great value as a filling-mate- 
rial are its toughness, softness, and pliability, which permit it to be readily 
adapted to the walls of the cavity ; its tenacity, which facilitates its intro- 
duction and consolidation ; and its resistance to mechanical abrasion. It, 
however, possesses an objectionable color, and yet it is the least objection- 
able in this respect of all the metals that are used for this purpose. 

Miller in testing for antiseptic properties in gold-foil found that un- 
annealed foil — Pack's pellets and Abbey's foil — retarded the growth of the 
mouth bacteria, while the same gold annealed had no effect. Some prepara- 
tions of platinum-gold and sponge-gold acted in a similar manner. 

Chemically, gold is inert as a filling-material. It possesses no thera- 
peutic property upon tooth-structure, and it is not acted upon by any 
substances which are found within the mouth or that enter this cavity. 

Gold-foil as used by the dentist for filling teeth is prepared in two dis- 
tinct forms, which are distinguished from each other by the terms cohesive 
and non-cohesive. These terms are applied to designate the distinctive 
quality of which each is possessed. 

Foils are manufactured from pure metal by the processes of beating and 
rolling. Absolute purity, however, is not essential in the manufacture of 
foils. A small amount of alloy does not injure the working qualities in 
the least. 

All light-weight foils are made by beating, and heavy foils by rolling. 

The bullion is first melted and poured into ingots of suitable size ; 
these are then rolled into thin ribbons about one inch wide and a little 
thicker than ordinary note-paper, the thickness being governed by the 
weight of the foil to be produced ; the ribbons are then cut into inch 
lengths, each of which will weigh two, three, four, five, or six grains, ac- 
cording to the weight of the foil it is desired to make. 

These squares are then laid between sheets of goldbeater' s-skins made 
from the intestines of bullocks ; vellum paper made to imitate the skins is 
now extensively used because of its cheapness. These skins are cut into 
five-inch squares, and from one hundred and sixty to one hundred and 
seventy of them piled one upon the other, with a square of rolled gold 
between each, and the pile wrapped in heavy parchment, being bound 
both ways, so that all of the edges are protected. 

This package is then placed upon a heavy stone block or pillar, three 
feet high by fourteen to fifteen inches square, and resting upon a lai-ge 
wooden block, which is set in the ground from three to four feet to give 
it solidity, the upper end or face of the stone pillar being smooth and 
polished. Then with a heavy, round-faced steel mallet the package is 
beaten with heavy blows, and after each stroke of the mallet it is turned 



256 OPERATIVE DENTISTRY. 

one-quarter around. The time consumed in beating out such a package of 
gold is usually from two to three hours. 

After the foil has been beaten to the desired thinness, the leaves are 
separated, trimmed, and placed in paper books ready for use. 

Boiled gold is made by passing it through specially prepared mills until 
the desired thinness is obtained. 

All foils as they come from the beater' s-skins or from the rollers are 
non-cohesive. The cohesive quality is developed by a process of slow- 
heating or annealing. 

The light-weight foils in both the cohesive and non-cohesive forms are 
those most commonly used, 2sTos. 3 to 6, and of these, Ko. 4 is generally 
preferred. These numbers indicate the weight of each sheet in grains. 

Boiled foil varies in weight from twenty to two hundred and forty grains 
to the sheet, and is always prepared in the cohesive form. Nos. 20 and 30 
are the most popular at the present time, although a few years ago the 
heavier foils were in great demand. 

Cohesive gold possesses in a high degree the quality of cohesiveness, 
which causes the surfaces when brought in contact under pressure to cohere 
or weld. 

A filling made with this gold forms a solid mass, and may be afterwards 
hammered or rolled into plate. This quality gives great value to this 
form of gold as a material for restoring the contour of the teeth, but ren- 
ders its adaptation to the cavity walls more difficult, as the cohesive quality 
makes it work stiff and hard under the plugger. 

Non-cohesive gold is devoid of the cohesive quality and will not cohere 
or weld under pressure. This quality of non-cohesiveness makes it soft 
and pliable, and permits the surfaces of the gold to slip or slide upon each 
other when under pressure. This form of gold is valuable for the filling 
of all sinqfle cavities, by reason of the fact that it is easy of adaptation to 
the walls of the cavity and can be very rapidly introduced. 

The difference between these two forms of gold does not appear to de- 
pend upon their degree of purity, but rather to some trifling change in the 
physical condition, the nature of which is not definitely understood. If 
non-cohesive gold is thoroughly annealed it becomes cohesive, while if 
cohesive gold is exposed for a time to the atmosphere it becomes non- 
cohesive. 

A few drops of aqua ammonia placed upon a pledget of cotton and left 
overnight in a box containing cohesive gold will render it non-cohesive, 
while the cohesive quality may again be restored by annealing. 

The non-cohesive quality would therefore seem to be due to some accu- 
mulation or deposit formed upon the surface of the foil. "The process of 
annealing appears to drive this off, leaving the surfaces absolutely clean 
and thus rendering the foil cohesive. 

Black, in experimenting to ascertain the causes of this peculiarity, de- 
monstrated the fact that if gold foil is subjected to the fumes of ammonia, 
hydrogen, hydrogen carbide, hydrogen phosphide, sulphur, phosphorus, or 
sulphurous acid gas, its cohesive quality is quickly destroyed. Annealing 
restored this quality except in those samples which had been exposed to 



TREATMENT OF CARIES BY OBTURATION, OR FILLING. 



257 



the fumes of sulphur and phosphorus. In these the cohesive properties 
of the foil were permanently destroyed. 

It is therefore important, especially during the winter months, that 
cohesive foil be excluded as much as possible from the atmosphere, which 
is then more or less impregnated with the gases arising from the combus- 
tion of coal. He further demonstrated that the fumes of ammonia have 
the power of preventing the deleterious effects of other gases upon the 
foil, and recommended that the foil be subjected to this gas by keeping with 
it in the drawer a vial of ammonium carbonate. 

Non-cohesive foil was the only preparation of gold used by the earlier 
operators in filling teeth. Fifty years ago the cohesive property of gold- 
foil had not been discovered, and yet what marvellous operations such men 
as "Westcott, Dwindle, Maynard, Clark, and others were able to make with, 
non-cohesive foil. Their skill in the use of this material was really won- 
derful, for many of them succeeded in making most beautiful contour 
operations in approximal cavities of bicuspids and molars, many of which 
have resisted decay and withstood the wear and tear of mastication for 
several decades without losing their beauty of form and finish. 

These same men, upon the discovery of the cohesive quality of gold- 
foil, saw the great advantages to be derived from the discovery, and adapted 
it at once, to the salvation of 
broken-down teeth that were 
beyond successful filling with 
non-cohesive foil, and which 
otherwise would have been 
condemned to the forceps. So 
enthusiastic did some of them 
become that they were not 
content with restoring the 
contour of one-half of a tooth, 
but even restored the whole 
crown. Restorations of this 
character with cohesive gold 
were later carried to a very 
high degree of perfection by 
Dr. Marshall Webb. The ac- 
companying illustration, Fig. 
376, shows the extent to which he carried such restorations, a, b, d, e, f, 
are restorations of from two-thirds to three-fourths of the crown, while 
c, g, and h show restorations of the entire crown. 

The differences in the working qualities of cohesive and non-cohesive 
gold-foil make it necessary to use two distinct methods of operating. 




NON-COHESIVE FOIL. 

Non-cohesive foil is best adapted to cavities which have four walls, such 
as are found upon any of the free surfaces of the crown. 

Successful operations can also be made with it in cavities having three 

17 



258 



OPERATIVE DENTISTRY. 



good walls, as, for instance, in compound, approximal cavities in the bi- 
cuspids and molars. 

Non-cohesive, unannealed, or soft foil is the most ductile of all the forms 
of gold used by the dentist, and for this reason it does not "ball" under 
the instrument, is very readily adapted to the walls of the cavity, and 
insures a moisture-tight plug. 

The method of introducing it into a prepared cavity is to first prepare the 
gold in the form of cylinders, ropes, ribbons, or pellets of various sizes and 
density, the cylinders and pellets a little longer than the depth of the 
cavity to be filled. 

The cylinders are prepared by winding a ribbon of foil around a small 
Swiss broach, the ropes by rolling a strip of foil in a napkin, and the 
pellets are made by tearing the foil into small fragments and rolling them 
between the thumb and index-finger. Cylinders, however, are to be pre- 
ferred to pellets, from the fact that they can be prepared with more uni- 
formity in size and length than is possible in making pellets. The cylin- 
ders should be made of such size and density that several will be required 

Fig. 377. 




to fill the cavity, and of such length that when placed upon their ends in 
the bottom of the cavity they will project slightly from the orifice. These 
may be obtained from the manufacturer already prepared, as shown in 
Fig. 377, but the writer always prefers to prepare the gold for each in- 

Fig. 379. 



Fig. 378. 




Foil-carriers (reduced). 




Cylinders and mats in 
the act of being intro- 
duced into a crown 
cavity. 



dividual case as it is presented rather than to depend upon material 
prepared in advance, as this is very rarely just what is required. 



TREATMENT OF CARIES BY OBTURATION, OR FILLING. 



259 



The cylinders or pellets are then placed in the cavity with foil-carriers 
(see Fig. 378), being arranged side by side around the circumference of 
the cavity and condensed against its walls with suitable pluggers. Other 
cylinders or pellets are placed in like manner, and these are condensed 
towards its walls by the use of the wedging process, and this method con- 
tinued until the filling is finally finished by a single hard- rolled pellet 
forced into the centre. 

No instruments are better adapted for this purpose than those shown 
in Fig. 380, made from patterns furnished by Dr. Bing. 

Fig. 380. 




Bing pluggers. 



The cylinders, if the filling has been properly introduced, should pro- 
ject a little above the surrounding tooth surface. These should now be 
thoroughly condensed by hand-pressure or the mallet. Large serrated, 
round-faced foot-pluggers, as shown in Fig. 381, are the best for this pur- 
pose, as pluggers with sharp angles are liable to pulverize the enamel 
margins, if by chance they should come in contact with them. Thorough 
condensation, directed always towards the cavity walls, is of the utmost 
importance in finishing the fillings. The surface should next be bur- 
nished, also towards the enamel margins, and the surplus gold cut away 
with finishing burs, stones, or the file, as the location of the filling may 
make most convenient, and the surface polished with sand-paper disks, 
emery strips, and pulverized pumice-stone or rouge, or burnished. 



260 OPERATIVE PENTISTRY, 

Many operators who use non-cohesive foil employ the hand mallet all 
through the operation in preference to the exclusive use of hand-pressure. 
The stroke of the mallet is entirely different from the tapping stroke used 
in welding cohesive foil. The object in malleting non-cohesive foil is to 
utilize to its fullest extent the spreading quality or flow of 4his 
Fig. 381. f orm f gold, and this can only he accomplished by a firm 
ft driving blow, such as would be used in driving a nail of the 

same size as the plugger-point with which the gold is being 
packed, or it may be expressed as a lingering stroke that follows 
the plugger and remains upon it until the force of the impact 
has been exerted to its fullest extent upon the gold immediately 
beneath the plugger. The stroke, however, must be graduated 
to the size of the plugger and the strength of the walls of the 
cavity, otherwise damage might be done by driving the point 
of the plugger against the margins of the cavity or fracturing 
its walls. 

In com/pound approximal cavities (mesio-morsal or disto-mor- 
sal) in the bicuspids and molars the filling is commenced at the 
plugged cervical wall by placing two or three cylinders side by side, with 
the ends projecting beyond the cavity, and condensing them 
against the cervical margin with broad-faced pluggers. This process is to 
be repeated until the morsal surface is nearly reached, when the cylinders 
should be condensed against the morsal margins with foot-shaped pluggers, 
and the filling finally finished in the centre with a rope or a single hard- 
rolled pellet. 

Final condensation should begin at the morsal surface and be gradually 
carried over to the approximal, using the round-faced foot-pluggers for 
this purpose. The amount of contour obtained by this method will de- 
pend upon the distance that the cylinders projected beyond the walls of 
the cavity at the apj)roxinial surface and the thoroughness with which 
they were condensed in building the filling. 

Many operators prefer to use non-cohesive foil for the base of the cavity 
and cohesive foil for the remainder. 

If this method be pursued it will be necessary to partially anneal the 
pellets which are to form the last layer of non-cohesive foil, as by this 
means the cohesive foil can be welded to it. Or the cohesive foil may be 
driven into the surface of the non-cohesive foil by small wedge-shaped 
pluggers. 

Another method is to pack non-cohesive foil against the walls of the 
cavity and over the margins, and finish the filling in the centre with cohe- 
sive foil. This was a favorite method with the late Dr. Allport, and one 
which he practised for many years. 

In approximal cavities in bicuspids and molars he always used non- 
cohesive foil at the cervical margin, claiming that he secured a better 
adaptation of the gold to the cervical wall than was possible with cohe- 
sive foil, and that from the fact that large cylinders or pellets were used 
for this purpose, and thoroughly condensed with a broad-faced foot-shaped 
plugger, there was less danger of injuring the cervical margin than when 



TREATMENT OF CARIES BY OBTURATION, OR FILLING. 261 

cohesive foil was used, as with the latter it was absolutely necessary to use 
small pieces of foil and condense them with small pointed pluggers to 
secure perfect adaptation, while the danger of bruising the cervical margin 
was greatly increased by the liability of the plugger to being driven 
through the gold. 

Hopes and ribbons are used by some operators in preference to cylinders 
and pellets. These are made from one to two inches in length, a sheet of 
foil being cut into two to four equal strips and rolled in a napkin to form 
ropes, or folded with a spatula to form ribbons. 

The method of introducing the rope and the ribbon is to grasp one end 
of it with the foil tweezers and carry it to the bottom of the cavity, and 
lightly pack it against the wall farthest from the operator, then fold it over 
and carry it again to the bottom of the cavity, condensing it against the 
fold first inserted, but allowing the upper end to project slightly above the 
margin of the cavity. After the cavity has been about half filled in this 
way, another rope or ribbon may be introduced in like manner and packed 
against the wall of the cavity nearest to the operator, then against the lat- 
eral walls, and the filling finally completed by packing and wedging an- 
other rope or ribbon into the open space left in the centre. The surface 
is then thoroughly condensed and finished in the manner described with 
the use of cylinders and pellets. This method is thought by some opera- 
tors to be superior to the use of cylinders, for the reason that the gold is 
more easily introduced and that it makes a more compact filling. This 
statement, however, is open to question in both of its features. 

Herbst Method. — Another method of packing non-cohesive gold is 
that introduced by Dr. Herbst, of Germany, which consists of adapting 
or modelling the gold to the walls of the cavity by means of burnishers 
rapidly rotated by the dental engine. The gold used for this purpose was 
a very soft form of cylinders especially prepared by Wolrab, of Bremen. 

Fillings introduced by this method show a most perfect adaptation of 
the gold to the walls of the cavity, are moisture-tight, as proved by their 
successful resistance of the carmine test. The surface of the filling pre- 
sents a burnished appearance, which is rendered very cohesive by the fric- 
tion and heat produced by the process of burnishing, so that each piece of 
gold as it is introduced adheres to the previous one which has been bur- 
nished into its position. The filling may be finished throughout by the 
same process, but better results are obtained by finishing with cohesive 
gold condensed by the mallet. 

The instruments recommended by Dr. Herbst for the introduction of 
the filling are shown in Fig. 382, and consist of eighteen burnishers, some 
of steel and others with blood-stone points of various form and size. 

It will be readily understood, however, that only the most accessible 
cavities can be successfully filled by this method ; those, for instance, pos- 
sessing four good walls, like the morsal cavities of the molars and bicuspids, 
being the most favorably located for this system. 

For anchoring the filling, no especial preparation of the cavity is re- 
quired other than that given to cavities which are to be filled with non- 
cohesive foil by the other method. 



262 



OPERATIVE PEXTISTRY. 



In starting the filling, the first cylinder introduced into the cavity 
should be large enough to cover the bottom, and it should be carried 
into position with a round hand-burnisher, and then followed with the 
engine-burnisher of the same size and form, and thoroughly adapted 

Fig. 382. 




1 J 11 




Herbst burnishers. 



to the floor of the cavity. Successive cylinders are then introduced and 
burnished against the walls of the cavity, keeping the edges next to the 
walls higher than the centre of the filling. As the filling nears completion, 
the cylinders should be so placed that they can be burnished against and 
over, the enamel margins. The centre of the filling can then be finished 
by adding other cylinders by the same method, or with cohesive gold, 
condensed with foot-pluggers and the mallet. Fillings made by the 
Herbst method are not so dense as those made with the mallet, and the 
surface does not wear so well, as it shows a tendency to flake and bruise 
under stress of mastication. Contour fillings cannot be as successfully 
made by this process as with cohesive gold, and yet, by the use of the 
matrix, thoroughly good approximal fillings have been introduced in the 
biouspids and molars, 

COHESIVE FOIL. 

Cohesive or annealed foil is stiff and harsh as compared with the 
"velvety" softness of non-cohesive foil. It does not work so easily as 
the latter, and requires an entirely different method of manipulation for 
its introduction. 

In the manipulation of cohesive foil the student must keep in mind 
two rules if he would be successful in its use : first, always to use small 
pieces of gold ; and second, to condense them with small plugger-points. 

Many faulty fillings have been made with cohesive gold by not ob- 
serving these two important rules. 

On account of the cohesive quality of this form of foil it has a tendency 
to "ball" under the plugger and draw away from the walls of the cavity ; 
while if used in large pieces there is constant danger of the mass clogging 
and bridging in the cavity, and thus making a porous and leaking filling. 

Cohesive foil is prepared for introduction into the prepared cavity in 
the form of loosely rolled ropes, ribbons, pellets, and mats. 

The loosely rolled ropes are made by dividing a sheet of No. 3 or No. 4 
foil into strips and rolling them in a napkin. Cohesive foil should never 
be handled with the unprotected fingers, as the moisture or other impurities 
upon the skin would destroy its welding properties. 

Pellets may be made by cutting the ropes into lengths varying from one- 
eighth to one-fourth of an inch. 



TREATMENT OF CARIES BY OBTURATION, OR FILLING. 263 

Bibbons are made by folding a sheet of the same foil with a spatula to 
any desired width. Twice folding reduces the sheet to one-fourth its 
original width ; this may be cut lengthwise in strips or ribbons from one- 
sixteenth to one-eighth of an inch in width. 

These ribbons are composed of four thicknesses of foil, and in this form 
they constitute one of the best methods of introducing cohesive foil. 

Mats are prepared by folding a half-sheet or a whole one into a ribbon 
about one-eighth of an inch wide and cutting it into suitable length for 
use in the case at hand. Ribbons and mats may also be made from No. 
20 or No. 30 foil of a single thickness by cutting it in strips of suitable 
widths and lengths. 

Some operators prefer the rolled gold to the beaten when using heavy 
foil, as it is claimed greater softness and ductility is obtained when the 
foil is prepared in this way. 

Introduction of Cohesive Foil. — In the introduction of cohesive 
foil, retention grooves or pits are necessary for starting the filling. The 
first jnece of gold introduced into the cavity should be firmly anchored by 
packing it into the retaining grooves or pits. This may be accomplished 
by holding the gold in position with an instrument held in the left hand, 
while it is packed into place with the plugger held in the right hand and 
the succeeding piece welded to it ; this process being repeated until the 
cavity is full. 

Care should be exercised that only a small quantity of gold shall at any 
time be under the plugger for condensation, and that each piece that comes 
in contact with a wall or margin of the cavity shall be thoroughly adapted 
to it without bruising the tooth-structure. The best results are only 
attainable by welding each lamina thoroughly to the preceding one. 
Hastily made fillings are usually faulty in their adaptation to the enamel 
margins, and sooner or later fail from leakage and recurrence of caries. 

Plugging Instruments. — Cohesive foil can be manipulated either by 
hand-pressure or mallet force. The plugger-points which are required 
for adapting this form of gold to the walls and margins of the cavity and 
for condensation are considerably smaller, and the serrations much finer 
than those used for non-cohesive gold. The forms which are in the most 
general use are the Yarney, Webb, Darby-Perry, Chappell, and Royce, 
as shown in Figs. 383, 384, 386, 387, and 388. 

Serrated instruments are not, however, absolutely necessary for pack- 
ing cohesive gold ; smooth points answer equally well with rough ones. 
Some operators use ivory points with smooth surfaces, and hand-pressure 
entirely in packing cohesive gold. The ideal surface for a plugger-point 
for welding cohesive gold is that formed by breaking hardened steel. The 
nearer the serrations reproduce the roughness of this surface the nearer 
the plugger-point will approach the most perfect form for welding cohesive 
foil. 

Mallet force or percussion, as a means of welding cohesive gold and 
condensing the surfaces of the filling, is now considered by the majority 
of operators as the only method by which perfect consolidation of a filling 
can be secured. Fillings of cohesive gold, made by hand-pressure in holes 



264 



OPERATIVE DENTISTRY. 



drilled in steel plates, do not weigh, as much as those made in the same 
plates with mallet force, which proves conclusively that more gold can be 



Fig. 383. 



s 



o 



li , 



Varney pluggers. 

Fig. 384. 





Fig. 385. 



Webb pluggers. 

packed into a cavity, and also more perfectly consolidated, by the use of 

the mallet than by hand-pressure alone. 

The mallet was first introduced as a means of packing gold- foil about 
the year 1838, by Dr. E. Merrit, of Pittsburg, 
Pa., who used a hand mallet for condensing the 
surface of fillings which had been introduced 
by hand-pressure. Earlier mention was made 
of this instrument for consolidating gold by 
Koecker in his "Principles of Dental Sur- 
gery," published in 1826. 

Mallet force, however, was not much used 
until the introduction of cohesive foil. The 
earlier operators with this form of gold soon 
discovered that in order to obtain perfect union 
of the surfaces percussion with the mallet was 
superior to hand-pressure. Various forms of 
hand- mallets were then introduced, made of 
wood, ivory, and metals, weighing from one- 
half ounce to two ounces. The metal mallets 

were made of soft steel, or of lead, block-tin, and various alloys encased in 

metal or wood rims. The steel mallet, Fig. 385, seems to be in the greatest 

favor at the present time. 




TREATMENT OF CARIES BY OBTURATION, OR PILLING. 



265 




Darby-Perry pluggers. 



Fig. 38' 



^5 



[ I 



Chappell pluggers. 
Fig, 388. 




Royce plugger-points 



266 



OPERATIVE DENTISTRY. 



Fig. 389. 




With the introduction of heavy gold-foils came the use of heavy mal- 
lets, weighing from three to four ounces or more. It Avas thought by 
those using these extremely heavy foils that heavy mallets 
were necessary in order to weld the surfaces of the foil. 
The extremes in heavy foil were soon found to be unde- 
sirable, except for finishing fillings, and with the decadence 
in the use of these foils the heavy mallet ceased to find 
advocates. 

Before the discovery that rubber sheeting or dam could 
be so utilized as to exclude the moisture from a cavity 

H during the operation of filling a tooth with gold the oper- 

||'o. I ator was obliged to employ one hand in holding the napkin, 
ft ; J while the other was used to introduce the gold and consoli- 
date it. This made it necessary to have an assistant to clo 
the malleting. For various reasons, however, suitable assist- 
ance could not always be obtained ; consequently inventive 
genius was called into activity, and several ingenious auto- 
matic mallets were devised, in which by the use of a spring 
a percussion stroke is delivered upon the plugger, similar to 
the stroke of the hand- mallet. 

The Snow & Lewis, the Foote, the Salmon, and the 
Abbott have found the greatest favor with the profession. 
Fig. 389 shows the Snow & Lewis instrument of the latest 
pattern. In using this instrument pressure is made upon 
the point of the plugger, as in packing gold by hand-pressure ; 
this liberates the spring, and the plunger in the upper end of 
the instrument is thrown forward with considerable force, the 
impact being expended upon the gold beneath the point of 
the plugger. The force of the stroke can be regulated to 
almost any degree to suit the desire of the operator. 

The Abbott instrument (Fig. 390) has a socket at each 
end of the handle or hand-piece, — one gives the ordinary 
forward stroke and the other a backward stroke. The latter 
was devised to carry especially formed plugger-points (Fig. 
391) for condensing gold upon the distal surfaces of bicuspids 
and molars. 

The Bonwill electro-magnetic mallet (Fig. 392) is by far 
the most perfect mechanical mallet that has been invented 
for condensing cohesive gold-foil. 

The strokes of this mallet are delivered with great rapidity 
and regularity, and with such force that the gold can be most perfectly con- 
densed. Its essential parts are a horseshoe magnet with a hinged armature 
and an automatic interrupter, held in a framework or handle to support 
the plngger-point. The electric current may be supplied by a Bunsen or 
Partz battery, a storage battery, or the controlled current from a dynamo. 
The novice will at first find some difficulty in using this instrument 
with satisfaction to himself and his patient, but with a little experience 
he will soon learn to control it and to appreciate its merits. 



Snow & Lewis 
automatic 
plugger. 



TREATMENT OF CARIES BY OBTURATION OR FILLING. 267 

Fig. 390. 



Abbott automatic mallet (reduced). 



Fig. 391 
f^\ f^\ <^\ ^ ^^ ^ 



^1 ^\ frsM 



" 



Plugger-points for Abbott's automatic mallet. 



Fig. 392. 



Fig. 393. 





Bomvill electro-magnetic mallet (reduced). 



Bonwill mechanical mallet. 



268 OPERATIVE DENTISTRY. 

The Bon will mechanical mallet (Fig. 393) was devised as an attachment 
to the dental engine, to be used as a substitute for the electro-magnetic 
mallet. Its essential parts are a small revolving wheel, having a lug upon 
its periphery, which strikes the plunger and delivers a blow upon the 
upper end of the plugging instrument. The force of the stroke is under 
perfect control, and the number of strokes per second may be increased 
from five to twenty, according to the speed at which the engine is run. 

Crystal or Sponge Gold. — This form of gold is made by two pro- 
cesses, one being chemical, the other electrolytic. It was first introduced 
to American dentists by the late Dr. Watts in 1853, under the name of 
sponge gold. It has been greatly modified and improved since that time, 
and now bears the name of crystal gold, and is one of the very best prepa- 
rations of cohesive gold. 

There are several ways of making this form of gold, but they are all 
embraced in three general methods, — viz., first, by precipitation ; secondly, 
by combining a certain quantity of mercury with the precipitate to obtain a defi- 
nite crystallization ; and thirdly, by electrolysis. Only pure metal can be used 
in the manufacture of this form of gold. 

In the first method gold is added to nitro- muriatic acid until a saturated 
solution is obtained. It is then precipitated by the addition of sulphate 
of iron or oxalic acid, the precipitant being added slowly so as to obtain a 
crystalline or fibrous form in the deposit. The precipitate is then care- 
fully washed and slowly heated to nearly a cherry- red heat. After cooling 
it is ready for use. 

The second method requires the combining of a definite quantity of pure 
mercury with the precipitate, and after allowing it to stand for a short 
time it is subjected to a mild heat, the mercury abstracted by treating the 
precipitate with dilute nitric acid, and washing it to remove the nitrate of 
mercury. It is then placed in a muffle and heated to a bright- red heat, 
after which it is ready for use as a filling-material. 

By these methods of manufacture there always remained an objection- 
able feature in the presence within the spongy mass of traces of nitric 
acid, which it was difficult or impossible to get rid of. 

Since the adoption of electrolysis in the place of the above methods of 
chemical precipitation this objectionable feature no longer exists. 

By this third method a certain amount of pure gold is dissolved in acids, 
the solution is then placed in a suitable glass vessel and plates of pure 
gold suspended in it. Then by means of an electric current the solution 
is decomposed and the gold deposited in beautiful feathery crystals. 

As fast as the solution loses its gold by the deposition of the crystals 
it is resupplied by the plates suspended in it. The deposited gold is then 
removed and washed to free it from any trace of the acids which held it in 
solution, and it is ready for use. 

Gold prepared by this process manifests great cohesive properties and 
is generally used in large contouring operations. Fillings made with this 
gold are as beautiful and as serviceable as any made with cohesive foil. 
The secret of success in the use of crystal gold is to introduce it into the 
cavity in small pieces, and to thoroughly condense each piece before add- 



TREATMENT OF CARIES BY OBTURATION, OR FILLING. 269 

ing another. Failures usually result from attempts to introduce large pieces, 
which clog under the plugger, or to imperfect condensation of the gold. 

Gold of this variety is sold in the form of bricks containing one-eighth 
of an ounce each. It is prepared for the cavity either by tearing it into 
small irregular pieces or by cutting it into small cubes with a sharp razor. 
Scissors should never be used for cutting this form of gold, as it condenses 
the edges which are cut and renders them stiff and difficult to work. Its 
working qualities are preserved by excluding it as much as possible from 
the atmosphere, and when used it should be well annealed. When freshly 
made it is sufficiently cohesive for general use without annealing. Many 
operators rely upon it for starting and finishing all fillings, but there is no 
form of gold that is so well adapted for starting fillings in shallow and 
irregular superficial cavities as this. 

Crystal Mat or Solila Gold. — Several other forms of crystal gold 
have from time to time been introduced to the profession. That known 
as crystal mat or solila gold has found favor with some operators. It is 
manufactured by De Trey, and was first introduced in the United States 
in 1897. It is sold in the form of thick sheets or mats, and differs from 
sponge gold in that it is more compact in form and the crystals are smaller 
and matted together. It does not work as readily as the sponge gold, and 
breaks and crumbles under the plugger to a much greater degree, causing 
considerable waste. It possesses no good features which are not possessed 
by Watts' s crystal gold except that it is more plastic. Deep undercuts 
and retaining-pits are not necessary for the retention of this gold. Cavities 
having three or four walls may be prepared as for plasties. Hand-press- 
ure and broad-faced pluggers are best for working this gold. On account 
of its tendency to break and crumble under the plugger it is difficult 
to use it for contour work where a matrix cannot be used. In simple 
cavities and in approximal cavities where the matrix is admissible it 
makes a beautiful and serviceable filling and with little waste of material. 

In annealing this gold, it should never be heated to a cherry-red ; 
annealing just short of this point gives the best results. 

In starting the filling a large piece should be used, large enough to 
cover the bottom of the cavity, and this thoroughly condensed against the 
walls. Smaller pieces should be used in building the balance of the filling, 
care being taken to thoroughly condense each piece before another is added. 

Small instruments should be used for condensing the filling against 
the enamel margins, as perfect adaptations cannot be secured with large 
pluggers. 

Operators who are accustomed to using non-cohesive foil will experience 
the least trouble in its manipulation, as the methods used in its introduc- 
tion and consolidation are quite similar. The ordinary methods should be 
followed in finishing and polishing the filling. 

Moss fibre gold, manufactured by the S. S. White Dental Manu- 
facturing Company is the latest (1898) form of sponge gold that has been 
introduced to the profession. It is an exceedingly soft, tough, cohesive 
gold, and possesses these qualities in a much larger degree, perhaps, than 
any other sponge gold upon the market. It is easily adapted to the walls 



270 OPERATIVE DENTISTRY. 

of the cavity, permits of extensive contouring, and when condensed pre- 
sents a hard, tough surface, and takes a beautiful finish. 

Deep undercuts or retaining-pits are not necessary in order to start a 
filling. The floor of the cavity should be as nearly flat as is possible, and 
the retentive shape given to it should be the same as for non-cohesive foil. 

Bound- faced pluggers with fine, shallow serrations, like the Eoyce 
instruments, are the best for packing and condensing this form of gold. 

Small pieces of gold only should be used. Large pieces cause bridging 
and result in a porous filling. 

In introducing the gold, each piece should be placed in the position 
required, and first "patted" with the plugger until evenly condensed, and 
then thoroughly condensed with hand-pressure or the mallet before another 
piece is added. Heavy malleting is not needed to condense this gold. 

Care must be exercised in annealing "moss fibre gold" not to overheat 
it. Under no circumstances should it be brought into contact with the 
flame of the lamp. Slightly warming the gold over a lamp upon a sheet 
of mica is all that is required. Overheating makes it hard and gives it 
a tendency to "ball" under the plugger. Extensive contour operations 
can be made with it more easily than with Watts' s crystal gold. 

Gold-and-Platinum Foil. — This form of foil was first suggested by 
Moffet, of Boston, and is a combination of gold and platinum. It is made by 
"sweating" together an ingot of gold and one of platinum and then rolling 
to any thickness desired. 'No. 20 and No. 30 are the thicknesses generally 
made. It has the appearance of gold-foil before it is introduced into the 
cavity, but the condensing process brings out the color of the platinum. 

This form of gold was in great favor a few years ago for restoring the 
morsal edges and labial surfaces of incisor and cuspid teeth, and for fin- 
ishing fillings upon the morsal surfaces of bicuspids and molars. The 
advantages claimed for it over gold alone are its better, or, rather, less 
conspicuous color and its greater hardness. 

It is prepared for use by cutting the foil into narrow strips or ribbons, 
and after being freshly annealed it is welded to the gold filling in the 
same manner as heavy gold-foil. Especial care should be exercised, how- 
ever, in its introduction to see that each layer is thoroughly welded over 
its whole surface before another piece is added. Mallet force is superior to 
hand-pressure in its condensation, and round-faced foot-pluggers with fine 
serrations give the best results. 

On account of the stiffness of this form of foil it should be used only 
for the purposes just enumerated. To attempt to use it to fill the body of 
a cavity would only end in a disastrous failure, either by fracturing the 
walls of the cavity from the force necessary to condense it or from faulty 
adaptation to the walls and margins inviting secondary decay. 

Annealing Process. — All metals become more or less stiff and hard 
by the process- of hammering and rolling. Gold-foil which has been made 
by either of these processes has, when it comes from the beater' s-skins or 
the rollers, lost its softness and ductility. To restore these qualities it 
becomes necessary to heat it. This process is termed annealing. The 
amount of heat used, and the length of time to which the foil is subjected 



TREATMENT OF CARIES BY OBTURATION, OR FILLING. 



271 



to it, will depend upon the degree of softness or of cohesiveness desired. 
All pure foil is rendered cohesive by annealing, but certain non-cohesive 
foils — those in which it is claimed iron has been used as an alloy — may be 
rendered soft and ductile by annealing without rendering them cohesive. 
Freshly made cohesive foil does not need to be reannealed except for con- 
tour work. Exposure to the atmosphere, however, soon renders it non- 
cohesive and makes reannealing necessary if contouring is contemplated. 

The alcohol flame or the gas flame from a Bunsen burner are generally 
used for the purpose of annealing. Some operators hold the piece of foil 
in the flame, others hold it just above, thus heating it to the desired de- 
gree. Others use annealing trays made of mica, Russia iron, or platinum, 
which are held over the flame of the alcohol lamp or gas-jet. The latter 
method is the best, for the reason that it excludes the possibility of dele- 
terious substances like carbon, sulphur, or phosphorus being deposited 
upon the gold from the combustion of the lamp-wick, or particles of sul- 
phur or phosphorus which have been dropped upon the wick in igniting 
it with a match, or in the case of the Bunsen burner, from imperfect com- 
bustion of the gas, which might deposit carbon or sulphur. 

Fig. 394. 




Custer electric gold annealer. 
Fig. 395. 




Kerr electric gold annealer. 

Electric Annealing Tray. — The neatest and also the most satisfactory 
devices for annealing gold are the electric annealing tray of Custer, shown 
in Fig. 394, and that of Kerr, shown in Fig. 395. 

By these devices any degree of heat that may be desired can be obtained, 
and with a uniformity not possible with any other device or method. 



CHAPTER XVIII. 



CONSIDERATIONS IN FILLING- SPECIAL CLASSES OF CAYITIES. 



Fig. 396. 



I. Simple Cavities upon Exposed Surfaces. — This class of cavities 

presents the most simple forms of fillings in the whole range of operative 

procedures upon the teeth. 

Cavities which are situated upon the labial surfaces of 
incisors and cuspids, especially when they have involved the 
cervix and extended beneath the margin of the gum, often 
present serious difficulties to the introduction of gold, which 
test the ingenuity, skill, and patience of the operator, as well 
as the fortitude of the patient. 

One of the most formidable difficulties to be overcome is 
the adjustment of the rubber dam to those cases in which the 
cavity extends beneath the free margin of the gum. This 
may sometimes be accomplished by passing a ligature around 
the cervix of the tooth and forcibly carrying it towards the 
apex, until the dam passes beyond the border of the cavity, 
or the gum may be held away by the aid of the gum retractor, 
shown in Fig. 396. 

It is always best to include in the rubber dam not only 
the tooth to be operated upon, but at least one upon either 
side of it. The How cervix clamp, shown in Fig. 397, often 
serves a good purpose in retaining the rubber dam in position, 

as do also the Libby clamp (Fig. 398), the Johnson lever clamp (Fig. 399), 

and the Dunn clamp (Figs. 400 and 401). 



Gum retractor 
(reduced). 



Fig. 397. 



Fig. 398. 





How cervix clamp. 



Libby clamp. 



It is sometimes necessary to slit the edge of the gum above the cavity 
in order to gain a clear view of the gingival margin and to permit the 
rubber dam to go above it. 

Cavities occurring in the labial surfaces of the incisors and cuspids are 
generally located either at the cervix or in the frequent imperfections of 
272 



CONSIDERATIONS IN FILLING SPECIAL CLASSES OF CAVITIES. 273 



Fig. 399. 




the enamel, due to developmental defects. As a rule they are shallow, and 
therefore need to be given a good retentive form, either by slightly en- 
larging the cavity at the bottom or by forming small 
retaining-pits in the extremities. Cohesive foil or 
crystal gold are the best for filling this class of cavi- 
ties. The filling should be started in one of the ex- 
tremities, care being taken that the first piece of gold 
is securely anchored and the balance of the filling 
built upon this. Many operators finish such fillings 
with platinum-gold foil, as the color is less conspicuous 
than pure gold. Figs. 402 and 403 show the location 
of fillings of this class. 

Cavities occurring upon the lingual surface of the 
incisors are generally confined to the laterals, and are 
the result of developmental defects, as shown in the 
imperfect closure of the pit or fissure at the base of 
the cingulum. These cavities are usually small, and 
are readily filled with a narrow ribbon of non-cohesive 
foil and finished with cohesive ; or the entire cavity 
may be filled with a narrow ribbon of cohesive foil. Such a filling is shown 
in Fig. 404. 

Fig. 401. 



Fig. 400 



Johnson lever clamp. 




Caries rarely attacks the morsal edge of the incisors and cuspids, except 
as the result of imperfections in development, from mechanical abrasion, 
or from traumatic injuries which fracture the enamel. Consequently the 
operation of filling is usually confined to artificial cavities, made for the 
purpose of protecting the morsal edges against the loss of tooth-substance 
from mechanical or chemical abrasion, or for lengthening the teeth when 
it is desired to l ' open the bite. ' ' 

Cavities prepared for this purpose must have strong retentive form, as 
fillings of this class are constantly subjected to great stress. Many opera- 

18 



274 OPEEATIVE DENTISTRY. 

tors are in the habit of inserting a couple of ' ' Mack' ' screws in the arti- 
ficially formed cavity, one near each extremity, as shown in Fig. 405. 
These add very greatly to the retentive strength of the cavity and make 
it very difficult to dislodge such a filling. 

Care must be exercised in setting the screws not to encroach upon the 
pulp. 

Fig. 406. 
Fig. 405. /~s x~\ >s- 




4 




Cohesive gold only should be used for building up these fillings. It 
may be either foil or crystal gold, as suits the fancy or the ability of the 
operator to manipulate one form of gold better than another. In making 
the choice he should always select that form of gold with which he is con- 
fident the best filling can be made. In starting the filling it is advisable 
to begin at one extremity of the cavity by anchoring the gold in the under- 
cut or retaining-pits, then repeat the process in the other extremity, and 
afterwards connect them together by a narrow ribbon laid upon the bottom 
of the cavity and folded back and forth, each fold being thoroughly con- 
densed upon the preceding one, care being taken to accurately fill the 
undercut before the building process is begun. 

Fillings in these locations must be thoroughly condensed with the 
mallet in order that they may obtain the greatest hardness possible to pure 
gold, as they are subjected to severe wear, which might result in abraded 
edges and flaking of the layers of gold. Fig. 406 shows the completed 
operation. 

Platinum-gold in narrow ribbons of No. 20 or No. 30 is preferred by 
some operators for all of that part of the filling which extends beyond the 
walls of the retaining cavity. The Bonwill electric mallet or the engine 
mallet are invaluable for packing the gold in these cases. 

Cavities occurring in the fissures and sulci of the morsal surface of the 
bicuspids and molars are the most accessible, and from their location offer 
the least difficulty to the introduction of gold fillings. Such cavities, if 
prepared with perpendicular or slightly undercut walls, need no other 
retentive shaping to insure firm anchorage of the filling. These cavities 
can be most rapidly and substantially filled with non- cohesive foil ; in fact, 
this is one of the most favorable locations for the use of non-cohesive foil. 
The gold can be introduced in the form of narrow ribbons, small cylinders, 
or small spindle-shaped pellets. 

In introducing ribbons, one end should be grasped with the foil-pliers 
and carried to the bottom of the cavity, at that point which is farthest from 
the operator, — this is a safe rule to follow in starting all classes of fillings, — 
and secured in place by a point held in the left hand, while with the pliers 
the ribbon is folded upon itself and carried again to the bottom of the cav- 
ity, and the fold packed firmly against its walls with a wedge-shaped or a 
foot-shaped plugger, but permitting the outer end of the ribbon to projee 1 






CONSIDERATIONS IX FILLING SPECIAL CLASSES OF CAVITIES, 275 

a little beyond the walls of the cavity. A second ribbon is now introduced 
in the same manner and packed against the wall nearest the operator. A 
third ribbon is introduced in the same manner and packed against the two 
opposite uncovered walls, and the operation completed by driving ribbons 
of cohesive foil into the filling, and finishing with heavy foil. Or, cylin- 

Fig. 407. 





ders may be introduced instead of ribbons, placing them on end in the cav- 
ity and packing them against the walls, finishing in the centre with a hard- 
rolled pellet, and then thoroughly condensing the projecting ends of the 
cylinders. Or the spindle-shaped pellets may be used, the tip of one end 
of which should be annealed by passing it in the flame of the spirit-lamp, 
and the annealed ends allowed to project slightly beyond the walls of the 
cavity. These are packed against the walls of the cavity after the same 
manner as cylinders, the centre finally receiving a pellet of cohesive gold. 
The ends of the pellets which project beyond the walls of the cavity are 
then condensed, and the surface finished with mats of cohesive foil, which 
welds without flaw to the surface formed by the annealed ends of the pellets. 
By this method the danger of the surface of the filling scaling off is obviated. 
Scaling off of the surface of the filling often occurs when the union of the 
cohesive gold with the balance of the filling is only mechanical. All fillings 
upon the morsal surfaces of the teeth should be made as hard as possible 
by thorough but judicious malleting. Fig. 407 shows the finished fillings. 
In cavities of larger size and depth, requiring the cutting away of the 
triangular ridge, and in those involving more considerable portions of the 
morsal surface of the molars, but in which the walls are perpendicular and 
strong (Figs. 408 and 409), cylinders will be found to offer the most rapid 
and efficient means of introducing the filling. These should be packed 

Fig. 408. Fig. 409. 





solidly against the walls in all directions, and the central portion filled by 
inserting cylinders, one after another, as long as space can be made for 
one with heavy wedge-shaped plnggers. The protruding ends should next 
be thoroughly condensed, and the surfaces finished in the manner described 
above. 

In broad, shallow cavities, or those of uneven depth, cohesive foil is 
better adapted for the purpose than the non-cohesive. Such cavities need 
to be shaped with undercuts at opposite points, or retaining-pits or grooves 
at the bottom of the cavity, and so placed as to offer the greatest resistance 
to mechanical dislodgement. 



276 OPERATIVE DENTISTRY. 

Tn the introduction of cohesive foil, the retaining-pits or grooves are 
filled first, and the subsequent layers of gold welded to thern and to each 
other. Cavities of uneven depth may be filled in the deepest portion with 
pellets of non-cohesive foil which have been rendered semi-cohesive at one 
end by annealing in the spirit-lamp, and the balance with ribbons, pellets, 
or mats of cohesive foil. In all deep cavities — those which approach very 
near to the pulp — this organ should be protected from thermal shock by 
the interposition of a layer of oxyphosphate cement or other suitable non- 
conducting medium. 

Cavities in the buccal surfaces of the bicuspids and molars are a little 
more inaccessible to operation than those of the class just described, and 
as a majority of these cavities are at the cervical border, difficulty is often 
experienced in adjusting the rubber dam so as to expose the cervical mar- 
gin of the cavity. The exclusion of moisture renders them but little more 
difficult to fill than those upon the morsal surfaces, except when located in 
the third molar, or when the patient's mouth is small, or the lips and 
cheeks are non-elastic. 

In deciding which form of gold shall be used in each individual case, 
the size and the depth of the cavity must be taken into consideration. 
Deep cavities are best filled with non-cohesive foil made into ribbons, 
cylinders, or pellets, and the surface finished with cohesive foil. Shallow 
cavities are always more easily filled with cohesive foil or crystal gold than 
with the non-cohesive. Watts' s crystal gold is most admirable for filling 
such cavities, as it requires but slight retentive shaping to obtain firm 
anchorage, and it does not possess the same tendency to "ball" or curl up 
at the edges and rock in the cavity as does cohesive foil. 

Especial attention should be given to the cervical margin in all those 
cavities which approach the gum line or extend beneath it. Non-cohesive 
foil will be more likely to insure a perfect sealing of the cavity at this point 
than cohesive foil by reason of its more ready adaptability. It is therefore 
advisable to place a thick mat or a large pellet of non-cohesive foil at the 
cervical margin, and make the balance of the filling with cohesive gold. 
Fig. 410 represents the finished filling. 

Cavities located upon the lingual surfaces of the bicuspids and molars 
are quite rare except in the lingual fissures of the superior molars. Occa- 

Fig. 410. Fig. 411. 




Filling in buccal surface of a 
bicuspid. 



sionally, however, they are found in teeth of defective development, and 
at the cervix and upon the roots of the teeth as a result of gingival reces- 
sion. Cavities of this class occurring in the inferior bicuspids and molars 
offer considerable difficulty to the introduction of gold fillings, and for this 



CONSIDERATIONS IN FILLING SPECIAL CLASSES OF CAVITIES. 277 

reason plastics are more often nsed in these locations than any other filling- 
material. When they occur in the superior molars, gold can be more read- 
ily introduced, though by reason of the limited accessibility of the cavity 
it becomes necessary to use hand- pressure for the greater part, if not the 
whole, of the operation. The same method of filling as described for cavi- 
ties upon the buccal surfaces should be pursued in filling the accessible 
cavities of this class. 

II. Simple Approximal Cavities. — This class of cavities are those 
which are found upon the approximal surfaces of all the teeth, but which 
do not involve any other surface, and are bounded by a continuous and 
unbroken wall. 

Cavities of this class occurring upon the approximal surfaces of the 
incisors and cuspids generally require preliminary treatment by temporary 
separation, either by tape and wedges, or the more rapid method with the 
Perry or other screw separator. If the cavity is small and well within 
the labio- and linguo-mesial or distal angles, the case presents no difficul- 
ties other than those growing out of its degree of inaccessibility. Such 
cavities may be two-thirds filled with non-cohesive foil, cut in narrow rib- 
bons, and the balance with cohesive foil. Curved pluggers are necessary 
in filling these cavities, on account of the proximity of the adjoining 
teeth. 

In cavities which involve a considerable portion of the approximal sur- 
face, retention is secured at the cervical border by a groove at the base of 
the cavity, combined with a retaining-pit at the extremities, and by a 
shallow undercut at the morsal border. Grooving the labial or lingual 
walls for the purpose of retention is to be deprecated, as it tends to 
weaken them, and increases the liability to fracture and dislodgement of 
the filling. 

The dentist who possesses the spirit of the true artist will at all times 
endeavor to conceal the gold as much as possible when he is called upon 
to place it in the anterior teeth. Consequently he will, whenever possible, 
conserve the labial wall of these teeth. The filling should be started in 
one of the retaining- pits at the extremity of the groove made at 
the cervical border, then the pit in the opposite extremity should Fig. 412. 
be filled, and both united by attaching a ribbon of gold from 
one to the other, and malleting it into the retaining groove. 
This gives a firm foundation upon which to build the filling 
and secures thorough adaptation of the gold to the cervical wall. 
The balance of the filling is then completed after the manner 
already described in filling simple cavities. Cohesive gold, 
either foil or crystal gold, is best adapted for fillings of this character. 
Fig. 412 shows the completed filling. 

Simple approximal cavities in the mesial or distal surfaces of the bicuspids 
and molars offer considerably more difficulty in filling than similar cavities 
in the anterior teeth, by reason of thefr less accessible position. Tempo- 
rary separation is always necessary in those cases presenting a normal ap- 
proximation of the teeth. When the cavities are large it often becomes 
necessary, in order to gain a clear view of all parts of the cavity, to con- 



278 OPERATIVE DENTISTRY. 

vert a simple into a compound one ; or this procedure may be necessary 
on account of the extension of the disease in directions which undermine 
the enamel, making it too frail to bear the stress of mastication. 

Simple cavities in these locations may be filled after the manner de- 
scribed for filling similar cavities in the anterior teeth, with the exception 
that by reason of their greater degree of inaccessibility hand-pressure 
becomes necessary in packing the gold for the greater part of the opera- 
tion. Non-cohesive foil can be used to advantage in this class of fillings 
if used in narrow ribbons, or loosely rolled cylinders or pellets, and the 
surface finished with cohesive foil. Some operators prefer cohesive gold 
throughout the operation. In such case the filling is started in small 
undercuts or pits made at the cervical border. The mallet is sometimes 

Fig. 414. 





used for condensing the surface, but it is less applicable to the distal sur- 
faces than to the mesial. Figs. 413 and 414 represent medium-sized fillings 
in the approximal surfaces of bicuspids and molars. 

III. Compound Cavities, — Compound cavities are those which in- 
volve two or more surfaces of the tooth, and, by reason of this, present the 
greatest difficulties in the operation of filling. 

Cavities which involve the mesio -labial and disto-labial surfaces of the 
incisors and cuspids are the least difficult of the series to fill, from the fact 
that an unobstructed view can be obtained of every part of the cavity by 
direct light and unaided vision. Each portion of the cavity should be so 
shaped as to give it an independent retentive form. Cohesive foil is best 
for filling this class of cavities, as the welding property is valuable in 
binding the fillings together, giving to them a proper contour and a more 
highly finished surface. Foil cut in ribbons and freshly annealed or crystal 
gold should always be used in this class of cavities. In starting these 
fillings the general rule of beginning all fillings at the point farthest from the 
operator holds good. When the approximal cavity is about two thirds full 
the filling in the labial cavity should be started and connected with the 
approximal filling, and the whole then treated as one filling ; in this way 
both fillings are bound solidly together, and dislodgement is impossible 
except by fracturing the tooth. 

As these fillings (Fig. 415) are constantly exposed to view, the greatest 
pains should be taken to give them an artistic form and finish by restoring 
the natural contour of the tooth, avoiding peculiar marginal lines, and so 
finishing the surface of the gold as to make it as little conspicuous as 
possible. 

Mesio-lingual and disto-lingual cavities in the incisors and cuspids may be 
filled (Fig. 416) in precisely the same manner as those cavities last de- 



CONSIDERATIONS IN FILLING SPECIAL CLASSES OP CAVITIES. 279 

scribed, care being taken that the retentive form of each cavity is such as 
to secure independent anchorage, and the gold so prepared that its welding 
property will be at its maximum degree. 

Cavities involving the mesio-morsal and disto-morsal surface of the 
incisors and cuspids are among the most difficult fillings to make substantial 



Fig. 415. 



Fig. 416. 





by reason of their form and exposed position to stress and leverage (Fig. 
417). The greatest care must therefore be exercised in securing firm an- 
chorage, and if this cannot be done within the formed cavity, it should 
be extended in some direction which will secure this without unnecessarily 
weakening the tooth. 

Figs. 418, 419, and 420 represent such methods of extension for anchor- 
age. In teeth having a broad morsal edge, additional anchorage may be 
secured by slightly grooving the labial and lingual walls at this point. 

Cohesive gold is best adapted to the requirements of such a filling, and 
used in such form as to preclude the possibility of the gold clogging under 

Fig. 420. 



Fig. 419. 






(From Dental Cosmos.) 

the instrument, as air-spaces resulting from imperfect consolidation of the 
foil are an element of weakness in the filling. 

The filling should be started at the cervical border and built up from 
this point, keeping the surface of the gold as nearly flat as possible, and 
restoring the contour as the filling progresses, care being taken to secure 
perfect adaptation of the gold to the labial and lingual enamel margins. 
An electric or engine mallet greatly facilitates the rapidity of the opera- 
tion, and insures more perfect consolidation of the gold than can be obtained 
by hand-pressure or the hand-mallet without the expenditure of an infinite 
amount of time and labor. To guard against bruising or flaking of the 
morsal edge of the filling, thorough condensation of the gold must be 
secured. Heavy foil, No. 20 or No. 30, if each piece is thoroughly welded 
to the surface of the filling before another is added, will make the hardest 
surface obtainable with gold. 




280 OPERATIVE DENTISTRY. 

Cavities which involve both approximal surfaces and the morsal edge of 
the incisors and cuspids — mesio-disto-morsal cavities — present the greatest 
difficulties from the mechanical stand-point in the whole range of opera- 
tions for restoring lost portions of tooth-structure with gold, but when the 
operation is finished it becomes, by reason of its form, one of the most 
secure fillings that it is possible to make. 

The filling may be started at the cervical border in the pits and grooves 
made for the purpose in either of the approximal cavities, preferably in 
that one which is farthest from the operator. Cohesive gold only is admis- 
sible in this class of fillings. The filling should be built 
up from the cervical border as squarely as possible until 
the morsal edge is reached. The same method is then 
employed in the approximal cavity nearest to the oper- 
ator, and when the morsal edge is reached the fillings are 
united by carrying the gold across the morsal edge, and 
finally finished at the approxiino-rnorsal angle nearest to 
the operator. Fig. 421 represents the completed filling. If the approxi- 
mal fillings have been securely anchored, the force applied upon their 
morsal extremities will have no tendency to dislodge them during the 
process of building the morsal edge, but if this preliminary step has not 
been properly taken, dislodgement is more than likely to occur before the 
operation is completed. 

Cavities involving the mesial and morsal surfaces — mesio-morsal — of the 
bicuspids and molars offer no difficulties which are not readily overcome. 
The only preliminary necessary for the preparation and filling of the 
cavity is the obtaining of such an amount of space by some of the methods 
of temporary separation as will enable the operator to gain a clear view 
of the cavity in all of its parts, and permit of the original form 
Fig. 422. f ^e tooth being restored by the insertion of a contour filling, 
as illustrated in Fig. 422. 

Failures in this class of fillings are prone to occur at the cer- 
vical border from secondary caries, and this is often due either 
to imperfect preparation of this portion of the cavity, to bruising 
of the enamel margin while condensing the gold against it, or to imperfect 
adaptation of the gold to the cervical wall. The greatest care should 
therefore be exercised in the preparation of the cavity and the introduc- 
tion of the gold. 

The cervical margin may be protected against bruising and perfect 
adaptation of the gold to the tooth secured by introducing a non-cohesive 
soft-rolled cylinder and condensing it against the cervical border. Many 
operators are in the habit of filling the cervical third of the cavity with 
non-cohesive cylinders and the balance with cohesive foil. Others prefer 
to fill the entire cavity with cohesive foil, using crystal gold at the cervical 
border to form the foundation of the filling, as on account of its great soft- 
ness it is easily placed and can be readily adapted to the walls of the 
cavity. 

A safe rule in all contour work is to extend the gold a little beyond the 
desired line of contour, in order that there may be opportunity for final 




CONSIDERATIONS IN FILLING SPECIAL CLASSES OF CAVITIES. 281 

shaping and polishing without destroying the artistic contour of the 
finished filling. Thorough condensation of the gold is an important factor 
in the stability of this class of fillings. Flow of gold fillings under stress 
is much less, as shown by Dr. Black, in fillings that had been thoroughly 
condensed and hardened by malleting than in those which had not been 
malleted. These fillings are subject to great stress, and therefore need to 
be thoroughly anchored in the morsal surface. Pig. 423 shows a method 
of anchorage obtained by extending some portion of the morsal cavity or 
by its natural form. 

Figs. 424 and 425 represent the method of " extension for prevention' ,? 
suggested by Dr. Black for filling bicuspids and molars. This method so 

Fig. 424. 






exposes the margins of the fillings that they can be kept clean with the 
tooth-brush, and it effectually secures them against a recurrence of caries 
with ordinary care of the mouth, provided the operation has been properly 
performed. 

Cavities situated upon the distal and morsal surfaces of the bicuspids 
and molars unite to form disto-morsal cavities. 

These are no different from the class just described except in their 
location, which adds very much to the difficulties in filling. All fill- 
ings of this class have to be made by the aid of reflected light, while 
the progress of the operation is viewed from the reflected image in the 
mirror. 

When the cavities are located in the posterior part of the mouth, as, 
for instance, in the second molars the difficulties of obtaining unobstructed 
light and vision are considerably enhanced. 

The operation of filling may be greatly simplified by the adjustment 
of a suitable matrix, thus converting a complicated operation into a sim- 
ple one. 

If the cavity has been given a proper retentive form, grooves and retain- 
ing-pits will not be needed, and the filling may be started with non-cohe- 
sive cylinders, mats, or pellets, thoroughly condensed against the cervical 
border and the matrix, which must be firmly fixed in position. After the 
cervical third of the cavity has been filled with non-cohesive gold, the bal- 
ance can be completed with cohesive gold in the manner described in the 
preceding class. 

Cavities occurring upon the morsal and buccal surfaces unite to form 
morso-buccal cavities. This class of compound cavities is usually confined 
to the lower molars and the upper third molars. They can usually be given 
a good retentive shape without forming grooves or retaining-pits. In the 
deep cavities non-cohesive gold can be used for the base of the filling and 
then finished with cohesive foil or crystal gold. In the shallower cavities 
it is best to use cohesive gold throughout. These fillings (Fig. 426) are 



282 OPERATIVE DENTISTRY. 

subjected to great stress and wear ; they should therefore, be made as solid 
and hard as possible, that they may not be dislodged or battered by the 
occlusion of the opposing tooth. 

Fig. 426. Fig. 427. 





Cavities involving the morsal and lingual surfaces are usually confined 
to the first and second superior molars. 

From the fact that these cavities are generally shallow, they should be 
filled throughout with cohesive gold. Their position makes them fairly easy 
of access. The morsal cavity is usually the deepest, and may be quite 
large, while the lingual cavity is narrow and shallow. In this case the 
morsal cavity being the largest should be filled first, the smaller cavity 
and the channel uniting them being filled by carrying ribbons of foil, 
which are first attached to the main filling, over into the channel and to 
the cervical extremity of the lingual cavity (Fig. 427). 

Cavities situated upon the mesial, distal, and morsal surfaces of the bi- 
cuspids and molars, uniting to form mesio-disto-morsal cavities, are of not 
uncommon occurrence. These cavities might be filled by the methods de- 
scribed for filling the same class of cavities occurring in the incisors and 
cuspids. Such operations, however, may be greatly simplified when made 
in the bicuspids and molars by the adjustment of a matrix to the distal 
surface. The band-matrix is sometimes used, but this is not so satisfactory, 
as it obstructs the light and vision to a considerable extent. Non-cohesive 
gold can be used to good advantage in forming the base, while cohesive 
foil should be used for the bulk of the filling. 

Fig. 429. 



Fig. 428. 



The filling should be started with a large, soft-rolled cylinder placed 
at the disto- cervical border and malleted into place. Others may be added 
until the entire floor of the cavity and mesio-cervical border are well cov- 
ered, after which cohesive gold may be used to complete the filling (Fig. 
428). 

When the buccal and lingual walls are frail and likely to fracture under 
the stress of mastication, the cusps may be cut away and the whole morsal 
surface restored with gold. This operation decreases the liability to frac- 






CONSIDERATIONS IN FILLING SPECIAL CLASSES OF CAVITIES. 283 

ture and, if well done, restores the tooth to its original form and preserves 
it for many years of usefulness. (See Fig. 429.) 

MATRICES. 

In filling compound approximal cavities — disto-morsal — in bicuspids 
and molars with the various forms of crystal or sponge gold, the matrix 
will be found of great service, not only in simplifying the cavity but in 
securing a more perfect adaptation of the gold to the enamel margin, and 
by facilitating the operation. In fact, many operators utilize these instru- 
ments in filling all disto-morsal cavities in the posterior teeth, no matter 
what form of gold may be used. Their greatest value, however, lies in 
their use as just indicated, and in the introduction of plastic materials. 

In the introduction of gold into disto-morsal cavities in the posterior 
part of the mouth, it is impossible to use a straight instrument for packing 
the gold ; it therefore becomes necessary to curve or bend the shaft of the 
plugger near its point to suitable angles for reaching the various surfaces 
of the cavity ; consequently the force or impact applied to the shaft of the 
instrument by the hand or the mallet is not directly expended upon the 
gold at the point of the plugger, but is more or less dissipated by the 
elasticity of the steel at the curve or angle, and by the tendency of each 
impact to drive the gold out of the cavity in a distal direction. By the 
adjustment of a suitable matrix a compound cavity is converted into a 
simple one, and the matrix used as a wall against which the gold may be 
packed. Objections have been raised to the use of these devices on 
account of the difficulty experienced in giving a proper contour to the 
approximal surfaces, and of securing perfect adaptation of the gold to 
the enamel margins which are contiguous to the matrix. 

These objections are readily overcome by a proper preparation of the 
cavity margins, which leaves them strong and straight, the careful adjust- 
ment of the matrix, and the same degree of skill exercised in introducing 
and condensing the gold against the margins that would be used in other 
cavities. 

Several forms of matrices have been invented, all of them possessing 
more or less valuable features. 

The Jack matrices, shown in Fig. 430, are so shaped as to provide for 
contouring, and are made in pairs, adapted for use upon the right and left 
sides of the mouth respectively. These are held in place against the tooth 
to be filled by wooden wedges driven between the matrix and the adjoin- 
ing tooth, the wedges being first dipped in sandarach varnish to keep them 
from slipping ; or it may be held in position by some quick -setting oxy- 
phosphate cement. The matrix is applied by an especially designed forceps, 
which grasps them firmly, permitting easy adjustment and withdrawal. 

When the rubber dam is used, this should be first adjusted, and the 
matrix applied afterwards. 

The matrix, to fulfil the object of its placement, must be immovably 
fixed against the tooth to be filled. Motion of the matrix results in im- 
perfect adaptation of the filling to the walls and margins by reason of the 
difficulty in packing the gold against a shifting body. 



284 



OPERATIVE DENTISTRY. 



To overcome this difficulty, loop and band matrices were devised of 
various forms and sizes to accord with the differences in the size of the 








Jack matrices and forceps. 



teeth. The Brophy and the Guilford patterns are the best of their kind, 
and are easy to adjust,— these are shown in Figs. 431 and 432. The only 
difficulty experienced in the use of loop or band matrices is to obtain a 
close adjustment at the cervix of the tooth, by reason of the smaller size 



Fig. 431. 




Brophy band matrices. 



of the tooth at this location as compared with the morsal surface of the 
crown. This difficulty may be overcome by driving a wooden wedge 
between the band and the adjoining tooth at the cervix, as previously 
described. 



CONSIDERATIONS IN FILLING SPECIAL CLASSES OF CAVITIES. 285 

The Woodward matrix (Fig. 433) is also an ingenious device, and in 
some features superior to the others just described. It has the great ad- 



Fig. 432. 



n n n n H n n 



i A 



f^ & 



p 




Guilford matrices, and manner of adjustment. 

vantage of being readily adapted to the cervix of the tooth, and is main- 
tained in position by means of two set screws, which rest against the tooth 
opposite the approximal cavity to be filled and act as separators. 

Fig. 433. 




Woodward double-screw matrices. 



A.s the teeth move under the pressure of the screws, it becomes neces- 
sary to occasionally tighten them. The space thus gained is of great value 
during the process of finishing the filling. 



TIN-FOIL. 

Chemically pure tin is furnished to the dentist in three forms, — foil, 
fibrous mats, and rolled strips. Foil is the form most generally used. 
This is beaten after the same manner as gold, and is furnished to the pro- 
fession usually in two weights, No. 3 and No. 4, the figures representing 



286 OPERATIVE DENTISTRY. 

the weight of the foil in grains. No. 3 foil is the weight in most general 
use. 

The fibrous mats or " fibrous tin''' is made from fine shavings of tin 
loosely pressed into mats. This form of tin has a tendency to crumble, 
and is therefore not so readily introduced into the cavity as foil, neither 
has it any advantages which are not possessed in an equal or higher degree 
by the foil. 

Boiled strips of tin are about the weight of No. 20 gold- foil, and are 
used in the same manner as ribbons of non-cohesive foil. 

Tin is one of the oldest filling-materials, and until the introduction of 
amalgam was the only substance at the disposal of the dentist for filling 
that class of teeth which were not considered worthy of the precious metal, 
or which for pecuniary reasons the patient could not afford to have filled 
with gold. 

It is much more ductile and easier of introduction than gold. It can 
be more readily adapted to frail cavity walls, and when properly intro- 
duced makes a perfectly moisture-tight plug. It does not readily oxidize, 
and but for its objectionable color and softness would be the very best mate- 
rial for filling frail teeth. Tin-foil when first made is cohesive to a certain 
degree, but this property is soon lost on being exposed to the atmosphere, 
and cannot be restored by annealing. 

The therapeutic action of tin upon tooth-structure is decidedly antiseptic 
when oxidation takes place. For this reason it cannot be too highly recom- 
mended for lining the cervical wall in approximal gold fillings, and as a 
filling-material in those cases in which there is a persistent recurrence of 
caries, associated with a thick, ropy, tenacious saliva, which in all proba- 
bility is due to the presence of gelatin-forming micro-organisms within 
the mouth. 

Tin does not conduct thermal changes so readily as gold, and conse- 
quently causes much less irritation to sensitive dentin. This fact led many 
of the older operators to line the bottom of all hypersensitive cavities, and 
those in which the pulp was nearly exposed, with a layer of tin-foil. 

Its most important use is for filling the temporary teeth and first perma- 
nent molars of children. The ease and rapidity with which it may be 
inserted and condensed, as well as its preservative qualities upon tooth- 
structure, make it the best material for this purpose that the dentist has at 
his command. 

TIN AND GOLD. 

Tin is also employed in combination with gold-foil. The metals are 
combined in various proportions ; some operators enclose a sheet of No. 4 
tin between two sheets of No. 4 gold-foil, and then either twist it into a 
rope or cut it into ribbons ; others fold a sheet of No. 3 tin in a sheet of 
No. 4 gold-foil, and then twist it into ropes of various sizes or cut it into 
ribbons of varying widths to suit the case in hand. The ropes may also be 
cut into pellets or the ribbons rolled into cylinders. 

This mixture of the metals works with about the same degree of soft- 
ness as tin alone, and can be as readily adapted to the walls of the cavity. 



CONSIDERATIONS IN FILLING SPECIAL CLASSES OF CAVITIES. 287 

Non-cohesive gold-foil is generally used in combination with tin, but 
some operators use cohesive foil, and then cover the surface of the filling 
with gold, claiming by this combination they are able to weld the gold to 
the tin and gold base. 

Fillings which are made of tin and gold combined have a yellowish- 
gray appearance when first finished, but they soon become more or less 
discolored upon the surface by oxidation. 

After a time some chemical change, which at present is not understood, 
takes place in the mass, rendering it exceedingly hard and giving it the 
appearance of an amalgam. It does not, however, stain the tooth-struc- 
ture, as might be expected, and seems to exert a very decided preventive 
effect upon caries. Such fillings will resist the attrition of mastication 
as well as gold, but they have the disadvantage of being unsightly in 
color, and should not therefore be placed in any conspicuous part of the 
mouth. 

Fillings made of this combination of metals do not conduct thermal 
changes so readily as gold alone, and consequently are better adapted to 
sensitive teeth. Such fillings are in every way superior to amalgam, and 
find their greatest field of usefulness in the bicuspids and molars during 
the periods of childhood and adolescence, and in persons subject to per- 
sistent caries. 

It can be introduced as rapidly as tin alone, makes a very durable fill- 
ing, and possesses a conserving action upon tooth -structure not possessed 
by gold alone or by amalgam. 

Methods of introducing Tin and Tin and Gold. — The methods 
of introducing fillings composed of tin and tin and gold, are the same as 
those used in introducing non-cohesive gold-foil. Some operators prefer 
to use cylinders and wedge-pointed pluggers and hand-pressure ; others 
use pellets and foot-shaped pluggers with the hand or mechanical mallet, 
finishing the filling by driving a hard-rolled pellet into the central por- 
tion of the plug, and then thoroughly condensing the surface towards the 
enamel margins with broad-faced pluggers and afterwards thoroughly 
burnishing. 

Fillings made from tin or tin and gold combined should be finished 
with the same degree of care and thoroughness as is expended upon those 
made from gold. The labor, however, is much less, as the material is not 
so resistant as gold. 

Finishing Fillings. — The beauty and the utility of gold fillings are 
greatly enhanced by perfect finishing. Fillings which have been well and 
carefully introduced sometimes fail for the reason that the margins have 
not been entirely freed from overhanging portions of gold, or the gold has 
not been cut down and finished flush with the enamel margins and highly 
polished. These imperfections are most often found at the cervical border 
of approximal fillings, particularly in the bicuspids and molars, where 
there is a tendency to bifurcation of the root, and the cavity extends 
beneath the gum, making a clear view of the cervical border very difficult 
to obtain. 

Fillings which present rough surfaces or imperfectly finished margins 



288 



OPERATIVE DENTISTRY 



invite recurrence of caries, by reason of the fact that these imperfections 
give lodgement to alimentary debris, where if it remains undisturbed it is 
soon attacked by the zymogenic bacteria, lactic acid is formed, and sooner 
or later secondary caries is established. The importance, therefore, of 
perfectly finishing all fillings cannot be over-estimated if the best results 
are to be obtained. 

In order to secure a surface in a gold filling that will receive a fine 
finish thorough condensation is of the greatest importance. Fillings which 
are imperfectly condensed cannot be made to take a smooth and highly 
polished surface, while after a little time the surfaces exposed to wear will 
become rough and pitted. 

In order to insure a good surface that will finish smoothly, many oper- 
ators are in the habit of using heavy foils for the last few layers of the 
filling. After the surface has been thoroughly condensed the burnisher 
should be vigorously applied, especially to the margins, in order to obtain 
perfect contact of the gold at these lines and to secure a compact and hard 
surface. Hand-burnishers (Fig. 434) or those revolved by the dental 
engine may be used for this purpose. The latter are made of various 
shapes, some having smooth surfaces, others corrugated surfaces, as shown 
in Fig. 435. 

Fig. 434. 




: 



Hand-burnishers. 



In all fillings the cavity should be filled a trifle fuller than the margins 
of the surface in which they are located, that there may be opportunity 
for a proper shaping of the surface of the filling to harmonize with the 
normal lines of contour. 



CONSIDERATIONS IN FILLING SPECIAL CLASSES OF CAVITIES. 289 

This shaping or dressing of simple cavities in the morsal surface of the 
bicuspids and molars may be accomplished by finishing-burs, such as are 

Fig. 435. 




Engine-burnishers. 

shown in Figs. 436 and 437. The "cut' 7 of these burs is much finer than 
that of cavity burs, and gives the surface of the filling a finish similar to 
that given to a flat surface with a fine file. The gold should be cut away 




Fig. 437. 



Disk burnishers. 



Plug-finishing burs. 



J Ul II 



until the margins of the cavity have been reached and all overlapping por- 
tions have been removed. The occlusion of the teeth should next be noted, 
and the surface of the filling made to conform to the occluding points or 
eminences of the morsal surface of the opposing teeth. As soon as a natural 
occlusion is obtained the surface of the filling should be polished, using 
fine powdered pumice and water, with a suitable wood point, as shown in 
Fig. 438, mounted in an engine porte-carrier. If the operator desires to 
give a burnished surface to the filling, this may be accomplished with a 
suitable engine-burnisher, lubricated with a solution of fine toilet soap in 
water. 

Fig. 438. 




Wood polishing-points. 

Large fillings in the morsal surfaces may be cut down with suitable 
corundum points or wheels. These instruments cut much more rapidly 
than the finishing-burs, and if kept wet with a stream of water from the 
syringe cause but little heating of the tooth. Fig. 439 shows a few of the 
various forms of these points and wheels. The best cutting and also the 
most durable corundum points and wheels are those made of fine corundum 
and vulcanized rubber. 

19 



290 



OPERATIVE DENTISTRY. 



In the use of corundum points for dressing down the surfaces of fillings 
there is danger, from the rapidity with which they cut, of grinding the 

Fig. 439. 





TTTI 



Corundum points and wheels. 

edges of the cavity and thus producing a thin and weakened margin. A 
final finish may be given to the surface of the filling by smoothing with 

Fig. 440. 




Arkansas, Hindostan, and Scotch stones. 

Arkansas or Hindostan stones of similar shapes (Fig. 440) and polishing 
with puinice or the burnisher. 

Fig. 441. 





Labial and buccal surface fillings are most 
readily finished with the corundum points, 
followed by the Arkansas stones and wood 
points carrying moistened pumice. The 
beauty of fillings lies in their perfect mar- 
gins and natural contour. Any overlap- 
ping of the gold gives the appearance of a 
ragged edge, while any degree of deviation 
from the normal convexity of the surface 
detracts from their beauty of outline. The 
final polishing may be done with felt or 
leather polishing- wheels or soft rubber pol- 
ishing-cups. The latter are especially valuable in finishing bucco- cervical 
fillings in bicuspids and labio- cervical fillings in the six anterior teeth. 



Soft rubber polishing-cups, 
corrugated inside. 



CONSIDERATIONS IN FILLING SPECIAL CLASSES OF CAVITIES. 291 

They are sliowu in Fig. 441. If a dead or satin finish is desired, — and this 
is best for the anterior portion of the mouth, because it is less conspicuous, 
— pundce moistened with water or glycerol will be found most satisfactory 
for this purpose, but if a brilliant finish is required, the pumice should 
be followed with precipitated chalk, oxide of tin, or rouge. 

Fillings which are located upon the approxvmal surfaces of the teeth are 
much more difficult to finish than those in any other portion, and conse- 
quently require a higher order of skill, while for obvious reasons there is 
no class of fillings which demand greater care in their finishing, or which 
repay the operator a higher reward for faithful service rendered. 

Fig. 442. 





Plug-trimmers and plug-finishing flies. 

As a consequence of the difficulties encountered in finishing this class 
of fillings a great variety of instruments have been devised to overcome 
them. The oldest of these are the thin flat files cut only upon one side 

Fig. 443. 



Approx: 

and both edges. Some of them are made with a spring temper, straight 
and curved ; others are tempered soft, and may be given any desired curve 
to suit the exigencies of the case in hand. These are 
shown in Fig. 442 and are most useful in the anterior 
part of the mouth. 

For trimming the cervical margins of the filling, 
the approximal trimmer shown in Fig. 443 is one of 
the most useful instruments devised for this purpose. 
This is file-cut upon one or both faces, and should gen- 
erally be used with a drawing motion, the blades of 
the file being set with that object in view. 

The sickle-shaped knife trimmers of Dr. Gordon 
White, shown in Fig. 444 are also admirable instru- 
ments for trimming the cervical margins of fillings. 

On account of the difficulties experienced in get- 
ting a clear view of the field of operation, it becomes 
necessary to examine the cervical margin by passing 
a fine probe or explorer over this portion of the filling, or, better still, 
floss-silk may be made to pass back and forth, from the cervix to the 




Sickle-shaped trimmers. 



292 



OPERATIVE DENTISTRY. 



morsal border of the filling, and if the probe does not catch or the floss- 
silk becomes frayed in the process, it may be presumed that the over- 
lapping edges of the filling have all been removed. The final shaping 
of the filling may be accomplished by emery tape or sand-paper strips 
drawn back and forth over the surface of the filling. When the margins 
are all well defined, the finishing may be completed with finer emery, 
silex, or buckhorn tape. A variety of these strips should always be on 
hand, comprising all the grits from the coarsest to the finest. The final 
polishing may be done with the soft rubber cups or thin soft rubber wheels 
charged with fine pumice. 

Approximal fillings in bicuspids and molars, because of the difficulties of 
apcess which are presented by their position, make them the most trouble- 
some of all fillings to finish. It therefore is necessary that the greatest 
care be exercised in this process, and that the cervical border receive par- 
ticular attention. Fillings which have been placed in those locations with- 
out the aid of a close-fitting matrix usually present a considerable over- 
lapping of the gold at the cervical border. The success of the filling, 
other things being equal, will depend largely upon the perfection with 
which the cervical margin is trimmed and finished. 

In those cases where a properly adjusted matrix has been used, the 
labor of trimming the margins and finishing the surface will be found to 
be greatly lessened. 

The pointed, right and left, curved files of Dr. Meriam, shown in Fig. 
445, will greatly facilitate the work of removing the overlapping edges of 




Fig. 446. 



gold at the cervical margin, and, supplemented with the trimmers just 
mentioned, will enable the operator to give the desired form to the surface 
of the filling. The final finishing can be accomplished with emery tape, 
sand-paper strips, etc., after the manner de- 
scribed above, or with emery cloth or sand- 
paper and cuttle-fish disks mounted upon 
suitable mandrels for use with the dental 
engine. These disks are made of various 
sizes, some of them having only a narrow rim 
of grit, the balance of the disk being plain 
(Fig. 446). The latter are valuable for polish- 
ing the cervical margin of contour approximal 
fillings, as it enables the operator to do this without cutting away the con- 
tour of the filling at the morsal border. Fig. 447 shows two of the popular 
forms of mandrels for carrying these disks. 




Thickened rim sand-paper disks. 



CONSIDERATIONS IN FILLING SPECIAL CLASSES OF CAVITIES. 293 

Especial attention should also be given to the morsal surface of those 
approxinial fillings which involve this surface of the tooth, that perfect 
occlusion may be secured. If the crushing stress of the jaws is expended 
upon such a filling, it is bound, sooner or later, to be dislodged, either 



mmumhi 



Fig. 447. 



Screw-head disk mandrel. 




The Morgan-Maxfield disk mandrel. 

from the flow of the gold under stress, the disturbance of the anchorage, 
or from fracture of the walls of the cavity. Such surfaces should be so 
shaped that the filling will not be called upon to carry more of the load 
than the surrounding portions of the morsal surface of the crown or of the 
other teeth. 

Fillings made of tin and tin and gold are finished in a similar manner. 

REPAIRING DEFECTIVE GOLD FILLINGS. 

Gold fillings which are defective from imperfect adaptation to an 
enamel margin, from recurrence of caries, or from fracture, are often 
susceptible to repair. 

These cases many times present problems which are by no means easy 
to solve. In the consideration of the question, each case offers a peculiar 
condition which makes it necessary to treat it upon its individual needs. 
This consideration must take into account the nature of the defect, its 
location and accessibility, the condition of the remaining filling, and 
the material best suited for repairing the defective condition. 

Defects which are the result of imperfect adaptation to an en'amel margin are 
usually discovered during the finishing of the filling, and if the rubber dam 
has not been removed, the defect may be readily repaired with cohesive 
gold. Sometimes it may be necessary to cut away the filling at the defec- 
tive point, forming a cavity in it of retentive shape. If the filling has 
been in contact with the saliva, the rubber dam must be adjusted, and the 
filling cleaned by bathing it with alcohol, ether, or chloroform, after which 
the defective point may be prepared as above, and filled with cohesive foil 
or crystal gold. 

Defects resulting from recurrence of caries are most often found at the 
cervical border of approxinial fillings. Thorough separation of the teeth 
is necessary to successfully repair such defects. 

Defects of this character can often be repaired most efficiently by using 
non-cohesive foil cut in narrow ribbons, and packed into the cavity fold 
after fold, allowing the loops to project beyond the margins of the cavity, 



294 OPERATIVE DENTISTRY. 

and when the cavity is full, thoroughly condensing the projecting loops 
and finishing the filling with emery strips, etc., in the usual manner. 

If cohesive gold is used, a retentive shape must be given to the cavity, 
and a groove or pit provided for holding in place the first piece of gold. 

The bicuspids and molars offer the most difficult cases to repair, by 
reason of their inaccessibility. Gold is the best material with which to 
make such repairs, provided the cavity can be made accessible ; but some- 
times it is not possible to accomplish this except by removing the entire 
filling, and this, when the filling is large and otherwise good, seems unfair 
to the patient, if there is a reasonable assurance of making a successful 
repair with one of the plastics. Gutta-percha is often successfully used 
in these places, but occasionally it will be found to undergo decomposition, 
and is therefore not as reliable as gold. The oxypkosphate cements are 
contraindicated on account of their tendency to dissolve and wash out 
after a brief period. Amalgam is more often used than any other plastic 
for this purpose, on account of the readiness with which it can be intro- 
duced into cavities that are entirely inaccessible to gold, and the greater 
assurance of making a good repair. It has the disadvantage, however, of 
becoming very black after a few weeks of contact with the gold, but this 
does not lessen its value as a tooth preserver. On account of the black 
discoloration which always follows this use of amalgam, it should not be 
used in the anterior teeth. 

After the amalgam has become hard, it should be finished as carefully 
as possible, by removing all overlapping edges and polishing in the usual 
way. 

Defects caused from fracture of portions of the cavity walls is a not in- 
frequent accident, and one which may be successfully repaired, provided 
the filling has been firmly anchored in other portions of the cavity and the 
tooth is sufficiently strong to warrant the necessary retentive shaping of 
the cavity to receive the repair. 

The incisors are prone to such accidents ; the most common being the 
loss of the mesio-morsal or disto-morsal angle when large approximal fillings 
are situated well towards the morsal edge. Repairs of this kind are diffi- 
cult to make, but they may be successfully accomplished by taking ad- 
vantage of the favorable conditions that are presented. Each case must 
be carefully studied and treated according to the indications. No rule can 
be laid down for such cases. The operator must depend upon his knowl- 
edge of mechanics and his ingenuity to suggest a way to overcome the 
difficulties of each case as it is presented. 

Anchorage may sometimes be secured by drilling a retain ing-pit in the 
filling at one angle, and another in the sound dentin at a different angle, 
or shallow retaining grooves or channels may be cut in the labial and lin- 
gual walls of the cavity and re-enforced by a pit drilled into the filling. 
Crystal gold will be found most serviceable in this class of operations. 

Accidents of this character sometimes occur in the bicuspids and the 
molars, most often in the bicuspids, especially when these teeth have been 
filled upon their mesial and distal surfaces, with the fillings uniting upon 
the morsal surface. The buccal or the lingual wall may be broken away 



CONSIDERATIONS IN FILLING SPECIAL CLASSES OF CAVITIES. 295 

by stress so applied between the cusps as to split off the weaker of these 
walls. 

The prospect of successfully repairing these cases will depend upon the 
security of the anchorage of the approximal fillings, and the opportunity 
for obtaining good anchorage at the cervical border and laterally in the 
approximal fillings. When the buccal wall is lost it would be better prac- 
tice, for cosmetic reasons, to amputate the balance of the crown and place 
an artificial crown upon the root. 

If the lingual wall is lost, the objection to restoring it with gold is not 
so strong. Crystal gold gives the most satisfactory results in all cases of 
this character. 

Occasionally amalgam can be used for restoring the lingual cusps of a 
second bicuspid, but the discoloration which eventually follows makes this 
substance objectionable. 

Fractures of a similar character occurring in the molars are, as a rule, 
less difficult to repair, as they will usually admit of the proper retentive 
shaping without the same degree of danger to the pulp as accompanies the 
operation in the bicuspids. In those cases of fracture which extend 
beneath the gum, the difficulties are increased by the hemorrhage likely to 
attend the operation, and the difficulty experienced in retaining the rubber 
dam in a position beyond the fracture. Mack's screws can sometimes be 
set in such position as to offer strong anchorage and not encroach upon 
the pulp. Under such circumstances they become a valuable adjunct to 
the other means of anchorage. Cohesive gold only can be used for such 
repairs, and the form usually indicated is Watts' s crystal gold. 



CHAPTER XIX. 
PLASTIC FILLING-MATERIALS. 

Definition. — Amalgam (from the Greek ap.a, together, and yap.ia, I 
marry), a combination of one or more metals with mercury. 

Amalgam. — The use of amalgam as a filling-material was first sug- 
gested in 1826 by M. Traveau, of Paris, under the name of ' ' Silver Paste, ' 7 
and it was first introduced in the United States about the year 1830 by 
two Frenchmen named Crawcour, under the high-sounding title of the 
11 Royal Mineral Succedaneum." It was a purely metallic compound, com- 
posed of silver and copper, — " coin silver" (silver, nine parts ; copper, one 
part), — which had been reduced to a coarse powder by filing and rendered 
plastic by the addition of mercury. The mixture consisted of fifty per 
cent, of mercury, forty-five per cent, of silver, and five per cent, of copper. 
Fillings made of this compound soon turned almost a jet-black color upon 
the surface, and stained the tooth to an almost equally dark or dark-green 
shade by the formation of various compounds of silver and copper with 
oxygen and sulphur, which penetrated the tubuli and even the pulp-canal, 
the effect of which, however, seemed to place the dental tissues in a posi- 
tion to more or less successfully withstand the action of the direct causes of 
caries, as was seemingly proved by specimens of teeth which had been 
filled with it for many years without further decay. 

Some have thought this preservative action to be due to the formation 
of the sulphate of copper, which is an antiseptic of considerable value. 
In corroboration of this supposition the fact has been stated that when 
wood has been treated with solutions of sulphate of copper it is rendered 
much more enduring, as is known to civil engineers. 

It has also often been noticed in opening old tombs in England that in 
the oak coffins which had been put together with copper nails the wood 
immediately surrounding the nails was in a state of perfect preservation, 
while the balance of the timber had literally crumbled to dust from decay. 
The inference is therefore drawn that inasmuch as the sulphate of copper 
preserves the wood that has been treated with it, tooth-structure will also 
be preserved if the tubuli are impregnated with this salt, as it destroys the 
bacteria already in the tubuli and renders the dental tissues an unfavora- 
ble soil for the growth of the lactic-acid-producing bacteria. 

The merits and demerits of amalgam as a filling- material have furnished 
a ' ' bone of contention' ' over which the profession has wrangled for years, 
and have been the cause of much heart-burning and bitterness. The strife 
and ill-feeling engendered between the contending parties ran so high at 
one time as to bring about a professional and almost a social ostracism of 
those who dared to advocate its use. 

The opponents of amalgam looked upon this material as an agent which 
was destined to degrade the profession and set at naught the achievements 



PLASTIC FILLING-MATERIALS. 297 

which, had beeu wrought with gold as a material for filling and saving 
teeth. 

It was a fact, also, in the earlier years of the amalgam controversy, that 
a large majority of those who used this material were men not worthy of 
the name of dentist, men who had not the skill to make a creditable ox3er- 
ation with gold 5 hence the contempt in which they were held by the better 
class of practitioners. This contempt was also heaped upon the material 
which had formed the basis of the controversy. A few, however, of the 
better class of practitioners, who had a scientific turn of mind, began an 
investigation into the merits and demerits of this material from the stand- 
point of science, and finally succeeded in clearing away much of error and 
misstatement upon both sides of the question. 

As a result of this labor, the prejudice which was at that time so strong 
has of late years been gradually dying out, while to-day many of those 
who were among its bitterest enemies admit that under certain circum- 
stances and pathologic conditions, amalgam has proved itself to be a 
very valuable adjunct to the armamentarium of the dentist for saving 
teeth. 

Since the first introduction of amalgam as a filling-material many im- 
provements have been made in its composition and in the methods of its 
manipulation. 

To the New Departure Triumvirate, Flagg, Chase, and Palmer, belongs 
the credit of placing amalgam upon a scientific basis as a filling-material, 
although the earlier efforts of Townsend, Walker, and Arrington to perfect 
this material by eliminating the main objectionable feature of discoloration 
should not be forgotten. 

Townsend, recognizing the one great demerit of the old form of amal- 
gam, introduced in 1855, after a long series of experiments, an alloy com- 
posed of forty-four and one-half parts of pure silver and fifty-five and 
one-half parts of pure tin. The progress gained by this formula was, 
however, very doubtful, although there was a marked improvement in the 
tendency to discoloration. This feature was more than counterbalanced 
by its greater degree of shrinkage, which caused leakage and secondary 
decay. 

The formula forty parts of silver and sixty parts of tin formed the 
basis of all the various alloys that were introduced to the profession from 
the time of Townsend until the New Departure Triumvirate gave to the 
profession the results of its researches into the nature and physical prop- 
erties of amalgams and other plastic filling- materials. These studies re- 
sulted in a radical change in the composition of the alloys used in making 
amalgams. The amount of silver was increased and the tin decreased, the 
basie formula being sixty parts of silver to forty parts of tin. 

The introduction of more scientific methods in the manufacture, prep- 
aration, and manipulation of amalgam and the other plastic filling- mate- 
rials has greatly increased their usefulness as therapeutic agents, and made 
it possible for the poor, by a limited expenditure of money, to have their 
teeth cared for and saved for years of comfort and usefulness, while, upon 
the other hand, the more exact knowledge gained of the nature of their 



298 OPERATIVE DENTISTRY. 

physical, chemical, and therapeutic properties has made it possible to 
apply them to particular pathologic couditions with a reasonable assurance 
that they will fulfil the requirements of the individual state or condition 
for which they were applied. 

THE NATURE AND PROPERTIES OF AMALGAM. 

One or more metals held in combination with mercury is termed an 
amalgam. Two or more metals combined by melting are termed an alloy. 
No combination of metals can be called an amalgam until they have been 
combined with mercury ; hence the combinations of metals used for the 
purpose of making an amalgam should be termed dental alloys, and not 
amalgams. No mixture or combination of metals can be regarded as an 
amalgam unless it has mercury as one of its component parts, and that " in 
sufficient quantity to exert a combining influence over the other metals." 
(Flagg.) 

Amalgams are classified according to the number of metals which they 
contain. Those containing two metals — as, for instance, copper and mer- 
cury — are termed binary ; those containing two metals in combination with 
mercury are termed ternary ; those containing three in combination with 
mercury are known as quaternary amalgams. 

Mercury has the property of dissolving or melting certain other metals 
of a higher fusing character. "The combinations thus formed are in the 
case of solid amalgams definite compounds, but in which there is only a 
feeble chemical affinity between the constituents. Liquid amalgams are 
merely solutions of the various metals in mercury, and not, as a rule, 
definite chemical compounds." (Watts.) 

Amalgams, however, may with correctness be classed as alloys. Mat- 
thiessen has suggested that " an alloy may be either (1) a solution of one 
metal in another, (2) a chemical combination, (3) a mechanical mixture, 
or (4) a solution or mixture of two or all of the foregoing." 

Kirk is of the opinion that in combining mercury with dental alloys a 
chemical combination is formed. He says, "In all amalgams which possess 
the quality of setting or hardening from a plastic mass, we have to deal 
almost certainly with a chemical combination. The property of setting is 
in itself an evidence of chemical combination, and the formation of many 
amalgams is attended with elevation of temperature, more or less marked, 
which is another indication of chemical combination. Changes of the 
volume of the mass attendant upon the act of setting still further indicate 
that chemical union of some portion of the constituent elements of the 
amalgam has taken place." 

The Physical Properties of Amalgam. — The peculiar physical 
properties of amalgams are, — viz., setting, contraction, expansion, flow, 
stability, color, conductivity. 

Setting. — Du Bois says, " Our present theory in regard to the forma- 
tion of an amalgam is, that metals which melt at comparatively high tem- 
peratures when brought under the fusing influence of mercury — which re- 
mains liquid at a temperature of — 30° F. — are melted into union with it." 
The setting, hardening, or crystallizing of the mass is therefore due to the 



PLASTIC FILLING-MATERIALS. 299 

secondary cooling effect exerted upon the mercury by the admixture of those 
metals which possess a high fusing-point, and that the higher the fusing- 
point of the metals amalgamated, the more rapid will be the process of 
setting. Platinum, however, presents an exception to this rule. 

Amalgams are decomposed by the application of heat sufficient to 
volatilize the mercury which holds the other metals in combination. 

During the process of setting, and for some time thereafter, nearly all 
amalgams undergo a change in volume and form. This change in volume 
may be either a contraction or an expansion. 

Contraction and Expansion. — Contraction, or "shrinking," and ex- 
pansion, or "bulging," of amalgams is, according to Flagg, in a general 
way in harmony with the natural contraction or expansion of the metals 
composing it, when passing from a fluid to a solid state. Those metals 
which lose their fluidity slowly, like tin, for instance, cause the greatest 
amount of contraction, while metals like gold and copper, which lose 
their fluidity quickly, and silver, which expands when passing from the 
fluid to the solid state, exert a controlling influence upon contraction. 

The contraction of an amalgam filling produces " cupping of the sur- 
face and a drawing away of the mass from the walls of the cavity, while 
expansion of an amalgam produces bulging of the surface. 

Black has shown, in bis studies upon the "Physical Character of Amal- 
gams," etc. (Dental Cosmos, 1895), that contraction and expansion of dental 
amalgams are influenced by many factors, — viz. : 

11 (1) To the composition of the alloy. 

11 (2) To the fineness of the cut of the alloy. 

" (3) To the amount of mercury used in amalgamation. 

11 (4) To the evenness with which the mercury is distributed. 

"(5) To the method of manipulation." 

Dental alloys which are composed of silver and tin — the tin in excess of the 
silver — contract very considerably during the process of setting, while in 
those containing silver in excess the contraction is notably lessened. The 
proportions of these metals which will produce an amalgam with the mini- 
mum amount of contraction has been demonstrated by Flagg, and later 
by Black, to be silver sixty-five per cent., tin thirty-five per cent. Se- 
ducing the amount of silver and increasing the tin produces an alloy 
which will form a contracting amalgam, while increasing the silver and 
decreasing the tin produces an expanding amalgam. 

Black in his experiments found that in all silver-tin amalgams in which 
the percentage of silver was below sixty per cent, contraction was the 
rule, the amount of contraction seemingly being governed by the relative 
proportions of the silver and tin contained in the alloy. He also found 
that contraction occurred during the first twenty-four hours, being greatest 
during the first two hours. A slight compensating expansion then occurred, 
lasting for from one to three days. During the process of expansion the 
amalgam softens very materially. This process he thinks is normal to all 
amalgams containing less than sixty per cent, of silver, as its absence is 
the exception. Slight contraction again follows the expansion, and this 
he thinks extends over an indefinite period. 



300 OPERATIVE DENTISTRY. 

In alloys containing more than sixty per cent, of silver there is no 
primary contraction, while in those containing eighty per cent, of silver 
and twenty per cent, of tin the expansion was very great, causing bulging 
or " spheroiding" of the surface of the filling. This condition was always 
notably present in the old, coin silver amalgam, which contained ninety 
per cent, of silver. 

The fineness of the cut of the alloys, also, seems to exert an influence upon 
the contraction and expansion of amalgams containing fifty to sixty per 
cent, of silver, for Black found alloys of the same grade or composition, if 
cut fine or comminuted into very fine particles, always contracted much 
more than when cut in moderately coarse filings. This was a constant 
condition with this grade of amalgam. He was unable to definitely ex- 
plain this condition, but states the facts that the reduction of the alloy to 
such fine particles causes them to take up more mercury, and that the re- 
sulting amalgam is much softer and contraction greater. 

The percentage of mercury contained in amalgam influences the con- 
traction and expansion to a greater or less degree. Black says, however, 
that it "is not so important a factor in the contraction of amalgam as he 
had supposed, and yet when the mass has been worked very dry the change 
of bulk has been markedly less, whether contraction or expansion." An 
excess of mercury in contracting amalgams increases the contraction, while 
in expanding amalgams it increases the expansion. 

He found that "soft fillings, or fillings made from a mass containing 
fifty per cent, or more of mercury, showed great irregularity in contrac- 
tion." 

This author also found that a difference of five per cent, of mercury, 
or even more, in the fifty to sixty per cent, silver alloys, did not materially 
affect the contraction, but when the mass was so dry that no mercury could 
be worked to the surface in the process of packing it into the cavity, there 
was a marked lessening of the contraction. 

The amount ofmercury required to amalgamate the different alloys 
depends largely upon the per cent, of silver which they contain. This 
fact has long been recognized. 

Black found that the increase of mercury to form a workable mass was 
not very noticeable until the amount of silver passed beyond sixty-five per 
cent. ; but with seventy per cent, silver alloys it became very difficult to 
amalgamate them with fifty per cent, of mercury ; while with eighty per 
cent, of silver, sixty per cent, of mercury was necessary to form a work- 
able amalgam. The increase in expansion became very notable with the 
increase in the percentage of mercury. 

He also discovered that an increase of mercury was necessary for com- 
plete amalgamation of those alloys which contained less than sixty per 
cent, of silver, though this increase was much less marked. Alloys which 
contain sixty per cent, of silver require less mercury to form a good 
workable mass than those containing any other proportion. 

These facts, and many others, are most graphically shown in the accom- 
panying table or exhibit of Dr. Black, "On the Contraction and Expansion 
of Amalgams." 



PLASTIC FILLING-MATERIALS. 



301 





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'dg'dg'dh 'SS'SS 'SS'SSiiS 
c ll 3> S!§ S g g;§ 5^ g^'S^ 



302 



OPERATIVE DENTISTRY. 



■ _+_ x 


$ *■■■■". 


9 i - |Z -*. 'i ± 


s? - H ' " " ■ " % 


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How mixed. 
Hand. 

Hand. 

Mortar. 

Hand. 
Hand. 

Hand. 
Hand. 
Hand. 


Per cent, of 
Mercury. 

41.08 

50 
32.39 

36.50 
37.65 

34.24 
35.02 
39.18 


Formulas. 

Silver 53.22 
Tin 45.88 
Copper 0.45 
Bismuth 0.45 

Do. 
Do. 

Silver 48 ' 
Tin 48 
Gold 4 

Do. 

Silver 60 
Tin 37 
Gold 3 

Silver 48.5 
Tin 48.5 
Platinum 3.0 

Silver 44.81 
Tin 52.78 
Gold 1.78 
Platinum 0.62 


O „ .cc ' o. 


Notes. 

Hand-pressure (43) 

Margins open, 0.2 to 0.8. 

Soft filling (15) 

Margins open very irregularly, O.U to 0.1. 

Pressed in with dynamometer (45) with a stress of 200 pounds 
Margins slightly raised. 

Margins open 0.2 to 0.3 all around. 

Mallet-pressure (30) 

Margins open slightly half-way around. 

Hand-pressure 

Margins open irregidarly from to O.S. 

Hand-pressure (50) 

Margins open all around from 0.2 to 0.6. 

Margins open all around from O.S to O.S. 



PLASTIC FILLING-MATERIALS. 



303 







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304 



OPERATIVE DENTISTRY. 



3 p 





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W »> * *> <C N >> °> 1 S 1 $£, 


How mixed. 
Mortar. 

Hand. 
Hand. 

Hand. 

* 

Hand. 

Mortar. 
Hand. 

Hand. 


Per cent, of 
Mercury. 

50 
33.48 
43.18 

50 
46.70 

50 
56.15 

46.36 


Formulse. 

Silver 41.92 
Tin 56.33 
Platinum 0.44 
Zinc 0.88 
Bismuth 0.44 

Do. 

Silver 47.06 
Tin 51.76 
Copper 0.94 
Zinc 0.24 

Do. 

Silver 42.83 
Tin 51.62 
Copper 4.65 
Aluminum 0.55 
Gold 0.01 

Silver 65 
Tin 30 
Copper 5 

Do. 

Silver 70 
Tin 30 


O <N <N CO CO ■* r- t- CO 


Notes. 

The mass was laid aside (85) for one hour and the filling then 
made by hand-pressure 

Margins open, 0.1 to 0.5. 

Burnished in. Material (45) very dry and crumbling 

Margins open, 0.1 to O.U. 

Hand-pressure (55) 

Margins open irregularly, 0.8 in widest point. 

Put in with the fingers 

Margins very bad and do not agree, with micrometer, open 1.0 in 
several places. 

Hand-pressure (65) 

Margins perfect. 

Hand-pressure. — This mix formed a dark semi-coherent mass 
that was difficult to pack 

Margins perfect. 

Burnished in. No mercury (30) could be removed 

Margins appear good. 

Hand-pressure (40) 

Perfect margins. 



PLASTIC FILLING-MATERIALS. 



305 





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20 



306 OPERATIVE DENTISTRY. 

It will be noticed by a reference to this exhibit that formula No. 1 — 
silver 65, tin 35, mercury 44.60, mixed in the hand— gave the best results, 
there being no change in volume by either contraction or expansion at the 
sixth day. 

The evenness with which the mercury is distributed through the mass appears 
to be a controlling factor in the contraction and expansion of amalgams. 
This investigator found that wringing or compressing the mass in a piece 
of linen or chamois-skin had the effect of improving the amalgam both in 
its working qualities and in the stability of the final product, independently 
of the removal of an excess of mercury, especially if the compression is 
maintained for a little time. This he found to be the case when the amal- 
gam was so dry that no mercury could be squeezed out of it, and suggests 
that the steady compression has the effect of producing an even distribu- 
tion of the mercury through the whole mass. 

The method of manipulation was also found by Black to be an important 
factor in controlling contraction in contracting amalgams and in obtaining 
good margins. In packing amalgams, he recommends that it should be 
introduced layer by layer, and the pressure so applied as to thoroughly 
condense the mass, without breaking it up or kneading it, and the softened 
material cut away with sharp spoon-shaped excavators before another layer 
is added, this process to be repeated until the cavity is full and a fine hard 
surface remains. To obtain good margins, the mass should be carefully 
compressed against the walls with a small instrument, but in such a way as 
not to break up the integrity of the partially packed material. 

Flow of amalgams, — change of mass from molecular motion under stress. 
This is a property which has been observed to be possessed by the majority 
of metals, and described as the flow of solids, but hitherto entirely unsus- 
pected as a property of amalgams until Black discovered it. In the "flow" 
of metals, iron, steel, gold, silver, etc., except tin and a few of the softer 
metals, a given stress will cause the metal to yield, spread, or flow. The 
phenomena occur immediately, and cease after a period of from one to two 
minutes after the stress is applied, even though the stress be maintained. 
The application of greater stress causes an increased flow, which again 
ceases until still greater stress is applied. 

Black has discovered that the flow of dental amalgams is very different 
from this. He says, ' ' When the flow of amalgam has begun, it continues 
so long as stress is maintained. No increase of the stress is required to 
maintain the flow, even after the area of the amalgam has been greatly 
increased by the flattening of the mass between plain surfaces. If a stress 
of fifty pounds be put upon a block of amalgam one-tenth of an inch square, 
and maintained for one hour, flow will occur at a certain rate ; if the stress 
is reduced to twenty-five pounds, the flow will continue, but at a reduced 
rate. There is a manifest disposition of the material to creep out from 
under a load. It will go slowly with a light stress, somewhat quicker with 
a heavier one, but it cannot be made to go very quickly with a very heavy 
stress ; but will instead break into fragments." 

This investigator also discovered that there was a vast difference in the 
strength of amalgams under stress. 



PLASTIC FILLING-MATEEIALS. 307 

Exhibit of the Physical Properties of Silver-Tin Amalgams. 



A mechanical mix of precipitates 
of the metals. Materials fur- 
nished by Dr. Ames, of Chicago 

Pressed in with serrated points, re- 
mo vine: no mercury 

Burnished in 

Weighed and mixed and used 
without wringing out ; fillings 
made at once 

Fillings made after forty minutes 

Made with hot instruments, after 

fifty minutes 



As the blocks were made the odd 
numbers were placed in one 
box and the even numbers in 
another, so that they should be 
alike, and the tests made two 
days apart. 



Pressed in 

Burnished in. 



Pressed in 

Burnished in. 



Pressed in 

Burnished in. 



Pressed in. . . . 
Burnished in. 



Pressed in 

Burnished in. 



Pressed in 

Burnished in. 



Pressed in. 
Burnished 



Pressed in 

Burnished in. 



Made with hot points. 



(Silver 60 

\ Tin 40 



(Silver 
(Tin 



42,15 I 
57.55/ 



f Silver 55 ) 
J Tin 40 y 

( Copper 5 J 



(Silver 53.22 

I Tin 45.88 

! Copper 0.45 

I Bismuth 0.45 



(Silver 48 

{ Tin 48 

I Gold 4 



(Silver 60 ) 
< Tin 37 y 

(Gold 3 j 



Silver 4S.5 

Tin 48.5 

Platinum 3.0 



Silver 44.81] 

Tin 52.78 I 

Gold 1.87 f 

Platinum 0.62 1 



(Silver 54.86) 

1 Tin 44.89 V 

I Zinc 0.25) 



55.61 
55.61 



38.58 
41.64 



Hum 
Hum 



KUV.I 
39.05 
39.05 



39.08 
38.71 
38.71 
38.71 



31.92 
31.92 
40.18 

Id. is 
40.1s 



30.31 



37.15 
37.45 

36.75 



10.65 
40.65 



Hand 

Mortai- 



IIand 
Hand 



Hand 
Mortar 
.Mortai- 



Hand 

Hand 
Hand 

Mortar 
Mortar 
Mortai- 



Hand 

Hand 
Hand 

Mortar 
Mortar 
Mortai- 



IIand 
Hand 



Hand 
Hand 

Mortar 



Mortar 
Mortar 



33.26 

30.90 

35.77 



5.12 
6.56 
11.75 



1 


20.49 


1 


22.05 


3 


30.65 


1 


31.97 


1 


40.16 



15.57 
24.59 
25.11 



31.01 
36.11 



SOS OPERATIVE DENTISTRY, 

Exhibit of the Physical Properties of Silver-Tin Amalgams. — Continued. 



Made with hot points. 



Packed lightly, without removing 
any mercury 

Packed heavily with small points, 
removing all mercury possible. . 

Mixed without wringing out and 
packed lightly without remov- 
ing any mercury 

Pressed in 

Burnished in 



Pressed in 

Burnished in 

Experimental alloys made by Dr. 
P. J. Kester, of' Chicago, espe- 
cially for investigation 

(No mercury could be removed 
from these mixes by wringing 
through muslin.) 

(With 50 per cent, of mercury 
the mix was a dark, semi-coherent 
powder that was extremely diffi- 
cult to pack.) 

(These mixes worked easily and 
well, , only that they set ' very 
quickly.) 



f Silver 54.86 

Tin 44.89 

I Zinc 0.25 

[Palladium 0.25 



'Silver 41.92] 

Tin 56.33 I 

Platinum 0.44 \ 

Zinc 0.88 I 

Bismuth 0.44 J 



'Silver 47.06 

Tin 51.70 

Copper 0.94 

Zinc 0.24 



Silver 42.83^ 

Tin 51.62 

Copper 4.65 
Aluminum 0.55 
Gold 0.01 j 



f Silver 
(Tin 



f Silver 
i Tin 



I0.X9 
10.61 
33.01 

30.29 



41.43 
41.43 



41.00 
38.74 



35.9.-, 
35.95 
31.15 
31.15 
31.15 



50.00 
50.00 

60.00 

6(UM> 
(iO.no 
(io.no 



Hand 
Mortar 
Hand 
Mortar 



Hand 
Hand 



Hand 
Mortar 



Hand 
Hand 
Mortar 

Mortar 
Mortar 



Hand 
Mortar 

Hand 
Hand 
Mortar 
Mortar 



26.92 

19.55 

14.96 
16.34 
22.44 



11.33 
19.92 



25.09 
24.48 



4.09 
8.13 
2.S.41 
16.40 
17.50 



7.41 
9.23 

2.40 
3.50 
4.24 
4.50 



Note.— In the above experimental alloys the increase of mercury required as the tin is diminished is 
very notable. It shows that after a certain point, not yet accurately determined, we cannot diminish 
the flow by diminishing the percentage of tin. 



The foregoing table gives the flow, crushing stress, etc., of a series 
of experiments conducted by Dr. Black with sixteen different formulae for 
dental amalgams. 

The flow of pure silver-tin alloys was found to range from two and one- 
half per cent, to ten per cent, under a stress of sixty pounds, the differ- 
ence depending upon the composition of the alloy, the fineness of the cut, 
and the special mode of manipulation. 

The silver-tin formulse ranged in composition from forty per cent, of 
silver and sixty per cent, of tin to sixty per cent, of silver and forty per 



PLASTIC FILLING-MATERIALS. 309 

cent, of tin. The addition of a small per cent, of copper had a tendency 
to somewhat diminish the flow and give greater strength under stress. 
All other metals which enter into the composition of dental alloys mark- 
edly increase the flow of the amalgam, but do not seem to materially injure 
the strength of the amalgam under stress. He thinks, however, that the 
crushing strength of an amalgam is not a test of its stability under stress, 
but looks upon the amount of flow as the important test. The great difficulty 
with the silver-tin amalgams is that they will gradually change in form 
under the stress of mastication, as was demonstrated in the laboratory ex- 
periments by subjecting specimens of hardened amalgam to an intermittent 
stress. 

The copper amalgams do not flow under stress, and the margins remain 
perfect. This was not the case with the silver-tin amalgams. Their disposi- 
tion to flow under the stress of mastication allows them to move in the 
cavity, and on account of this movement they do not retain perfect mar- 
gins, and thus, after a time, the way is opened for the establishment of 
secondary caries by reason of the re-entrance of the active agents of the 
disease. 

A careful study of the table in reference to the relative influence of the 
various metals entering into the composition of dental alloys upon the flow 
of amalgams will be found to be exceedingly interesting, from the fact 
that, coupled with the discovery that all silver-tin alloys containing less 
than sixty per cent, of silver contract or shrink during the process of 
setting and for some time thereafter, it explains the condition which after 
a few months or years almost universally exists, — defective margins and 
imperfect adaptation to the walls of the cavity of fillings made from these 
alloys. 

Annealing.— Dr. Black also made another important discovery while 
experimenting with alloys made by himself as to the influence of time 
upon cut alloys, or aging of the alloy, as it has been termed. 

Flagg, in his work on "Plastics and Plastic Fillings," claims that freshly 
cut alloys do not mix as well, neither do they give as good "setting," 
"shrinkage," "edge-strength," or " color" tests, as when properly "aged." 

Black in his experiments found the opposite of this to be true in rela- 
tion to the shrinkage test. Freshly cut alloys which when made into 
amalgams did not shrink, or might expand, were invariably found to 
shrink after aging. The explanation of this phenomenon at first seemed 
to be due to a slight oxidation of the particles of the cut alloy, by which 
its chemical relations to mercury were profoundly changed. Further ex- 
perimentation, covering several months of time, finally demonstrated the 
fact that neither oxidation nor time had anything whatever to do with the 
working qualities or the shrinkage of dental alloys. During these experi- 
ments the influence of temperature in aging of alloys was accidentally 
brought to his notice. He immediately set to work to verify or prove the 
error of the influence of this new factor, and finally discovered, after ex- 
haustive experiments, that the change was due to a molecular alteration 
in the particles of the cut alloy, induced by heat, or, in other words, it was 
due to a process of annealing or tempering. Various degrees of tempera- 



310 OPERATIVE DENTISTRY. 

ture were used, ranging from 110° to 212° F. ; but the lower tempera- 
ture produced the best results. 130° F. was found to be the temperature 
which produced the greatest amount of shrinkage. 

Each alloy was found to have a definite "shrinkage expansion range." 
In some this range is all shrinkage, in others all expansion, and in still 
others it is both expansion and shrinkage. It was also found that by 
annealing or tempering any of the shrinking or expanding alloys these 
physical properties could be reduced to any amount, provided the tem- 
perature was maintained for a certain period. 

Each alloy has its zero point of contraction or expansion, beyond 
which no amount of annealing has any effect. 

"The modified silver- tin alloys that have seventy-five per cent, of 
silver or more expand only. They cannot be made to shrink by aging, 
though their expansion can be greatly reduced. The same class of alloys 
containing as much as sixty-five per cent, of silver and less than seventy- 
five per cent, expand when freshly cut, and shrink when fully aged or 
tempered. Those containing from fifty to sixty-one or sixty-two per cent, 
of silver shrink only, but shrink much more when aged than when freshly 
cut. Those that contain less than fifty per cent, of silver first shrink and 
then expand. When fresh cut the expansion is the greater, when aged 
the shrinkage is the greater. 

"Alloys which contain sixty-five to seventy-five per cent, of silver 
are hard, and make hard and quick-setting amalgams ; they are also the 
strongest amalgams that can be made of silver and tin. Alloys containing 
less than sixty- five per cent, of silver are soft, and make soft, slow-setting 
amalgams. Alloys containing more than seventy-five per cent, of silver 
are soft, and make frail, slow-setting amalgams ; the slow-setting property 
occurs somewhat suddenly after passing the seventy-five per cent. 

"Alloys which suffer no alteration in volume when unannealed shrink 
when annealed." 

The tables given on page 311 show the extent of the change produced 
in the alloys by the process of annealing in the unmodified and the modified 
silver- tin alloys, and the influence of the modifying metals also upon the 
shrinkage, expansion, flow, and crushing strength. They also demonstrate 
the fact that less mercury is required to amalgamate a given sample of alloy 
when annealed than when unannealed, and that both the flow and crush- 
ing stress of amalgams made from annealed alloys are slightly increased. 

Stability. — The physical property of amalgams designated as stability 
or rigidity is the antithesis of "flow." That amalgam is the best, other 
things being equal, which flows the least, — in other words, is most stable, 
shrinks the least, and has the highest crushing strength. Such amalgams 
have been said to possess great "edge-strength." 

The term "edge-strength" was invented to designate the degree of re- 
sistance an edge or an angle of hardened amalgam offers to a force which 
on being applied might cause it to be fractured. 

It is evident, however, from the discovery of the property of flow under 
stress possessed by the "unmodified" and the " modified" silver-tin amal- 
gams, that it will be necessary to modify all former notions in relation to 



PLASTIC FILLING-MATERIALS. 

Exhibit of Unmodified Silver-Tin Alloys. 



311 



















How prepared. 


of 
Mercury. 


Shrinkage. 


Expansion. 


Flow. 


Crushing 






Stress. 


Silver. 
















40 


60 


Fresh-cut. 


45.78 


6 


7 


40.15 


178 


40 


60 


Annealed. 


34.14 


9 


3 


44.60 


186 


45 


55 


Fresh-cut. 


49.52 


4 


8 


25.46 


188 


45 


55 


Annealed. 


32.13 


11 


1 


28.57 


222 


50 


50 


Fresh-cut. 


51.18 


2 


O 


22.16 


232 


50 


50 


Annealed. 


37.58 


17 


1 


21.03 


245 


55 


45 


Fresh-cut. 


51.62 


2 


2 


19.66 


245 


55 


45 


Annealed. 


40.11 


18 





17.53 


276 


60 


40 


Fresh-cut, 


52.00 


1 





9.06 


239 


60 


40 


Annealed. 


39.80 


17 





14.10 


297 


65 


35 


Fresh-cut. 


52.00 





1 


3.67 


290 


65 


35 


Annealed. 


33.00 


10 





5.00 


335 


70 


30 


Fresh -cut, 


55.00 





14 


3.45 


316 


70 


30 


Annealed. 


40.00 


7 





4.67 


375 


72.5 


27.5 


Fresh-cut, 


55.00 





42 


3.92 


275 


72.5 


27.5 


Annealed. 


45.00 


3 





3.76 


362 


75 


25 


Fresh-cut, 


55.00 





60 


5.64 


258 


75 


25 


Annealed. 


50.00 





6 


5.40 


300 



Exhibit of Modified Silver-Tin Alloys. 



Modifying Metal. 



Gold 5 

Gold 5 

Platinum 5. 
Platinum 5. 
Copper 5 . . . 
Copper 5. . . 

Zinc 5 

Zinc 5 

Bismuth 5. . 
Bismuth 5. . 
Cadmium 5. 
Cadmium 5. 

Lead 5. 

Lead 5 

Aluminum 5 
Aluminum 1 
Aluminum 1 



65 

65 

66.75 

66.75 

61.75 

61.75 

61.75 

61.75 

61.75 

61.75 

61.75 

61.75 

61.75 

61.75 

61.75 

61.75 

61.75 

61.75 

61.75 

64.5 

64.5 



35 

35 

33.25 

33.25 

33.25 

33.25 

33.25 

33.25 

33.25 

33.25 

33.25 

33.25 

33.25 

33.25 

33.25 

33.25 

33.25 

33.25 

33.25 

34.5 

34.5 



How prepared. 



Fresh -cut. 
Annealed. 
Fresh-cut. 
Annealed. 
Fresh-cut. 
Annealed. 
Fresh-cut. 
Annealed. 
Fresh-cut. 
Annealed. 
Fresh-cut. 
Annealed. 
Fresh-cut. 
Annealed. 
Fresh-cut. 
Annealed. 
Fresh-cut. 
Annealed. 
Fresh-cut. 
Fresh-cut. 
Annealed. 











O £ 
















■£ 3 


03 


















cS 




£3 


'£ 




o 


Oh 


m 


w 


fc 


52.33 





1 


3.67 


33.00 


10 





5.00 


51.52 





4 


3.35 


33.53 


7 





5.06 


47.56 





1 


4.62 


30.35 


7 





6.07 


51.87 





9 


9.68 


37.33 


7 





8.20 


53.65 





23 


2.38 


35.60 


5 





3.50 


56.65 





68 


1.83 


40.65 





9 


2.07 


46.26 








4.78 


23.67 


6 





5.58 


57.57 





100 


6.40 


47.25 





5 


3.54 


44.17 





1 


4.88 


32.76 


10 





7.18 


65.00 





445 




46.98 





166 


12.60 


38.26 





48 


17.90 



A 9 



290 
335 
329 
380 
330 
395 
273 
352 
343 
416 
290 
345 
288 
308 
225 
290 
290 
276 

198 

213 



their rigidity, for certain of them possess great resistance to fracture of the 
edges or angles, and still under the stress of mastication evince a decided 
tendency to flow, and consequently to a disturbance of the margins. All 
are therefore more or less unstable, and still some of them might be said 
to possess great "edge-strength" when in reality they possess very little. 
It therefore becomes necessary to discard or to modify the generally ac- 



312 OPERATIVE DENTISTRY. 

cepted meaning of the term " edge-strength" to make it harmonize with 
the new data regarding the flow of all silver-tin amalgams under stress. 

Those amalgams which flow least have also the highest crushing strength, 
as will be seen by a reference to the above tables. The most stable ' ' un- 
modified silver-tin" amalgam contains 72.5 per cent, of silver and 27.5 per 
cent, of tin ; its shrinkage when annealed was 3 ; expansion, ; flow, 3.76 ; 
crushing stress, 382 pounds. 

The most stable modified silver-tin amalgams are those which contain 
gold and those which contain copper. 

The formula of the former is, silver, 61.75 ; tin, 33.25 ; gold, 5. Fresh- 
cut, shrinkage, ; expansion, 1 ; flow, 4.62 ; crushing stress, 330. An- 
nealed, shrinkage, 7 ; expansion, ; flow, 3.07 ; crushing stress, 395. 

The formula of the latter is, silver, 61.75 ; tin, 33.25 ; copper, 5. 
Fresh-cut, shrinkage, ; expansion, 23 ; flow, 2.38 ; crushing stress, 343. 
Annealed, shrinkage, 5 ; expansion, ; flow, 3.50 ; crushing stress, 416. 

Color. — The tendency of amalgam to discolor upon its surface through 
the action of oxygen and sulphur has restricted the use of this material 
to those portions of the mouth where the objectionable color would not 
attract attention. Ever since the early efforts of Townsend to manufacture 
a dental alloy that would not discolor, it has been the ambition of manu- 
facturers and individual experimenters to discover a formula which would 
produce an amalgam that would maintain its color under all conditions 
that are likely to be met in the mouth. The formula, silver 61.75, tin 
33.25, gold 5, comes nearest to making an amalgam that will not discolor. 
Flagg's formula, silver 58, tin 37, gold 5, also gives excellent results. 
The writer has for years made an alloy containing silver 65, tin 30, gold 
5, which has stood the clinical test of twenty years without discoloration, 
and shows as good margins as many gold fillings which have done service 
in the same locations for a like period of time. 

The discoloration of amalgam is not confined alone to the exposed sur- 
faces of the filling, but often extends to the surfaces which lie against the 
dentin, causing discoloration of that tissue. This discoloration of the den- 
tin occurs most frequently under fillings which shrink or have been im- 
properly introduced, or in which secondary caries is progressing, causing 
leakage. 

This discoloration may be shallow or deep according to the character of 
the composition of the alloy, and is due to the formation of metallic sul- 
phides, from the decomposition of albuminous substances and the genera- 
tion of hydrogen sulphide. Black discolorations are found in amalgams 
containing silver and copper ; yellowish stains in those containing cadmium. 

To prevent discoloration of the dentin many operators are in the habit 
of lining the cavity with zinc oxyphosphate cement, or other barrier, before 
introducing the amalgam. 

Conductivity. — Amalgam as a conductor of heat and cold stands mid- 
way between gold and the basic zinc cements in the scale of the filling- 
materials. As a* conductor of electric currents it stands next below gold. 

On account of the fact that amalgam is often used to fill cavities which 
are very large and dangerously near to the pulp, this organ should be pro- 



PLASTIC FILLING-MATERIALS. 



313 



tected from the dangers of thermal shock by the interposition of some low- 
conducting filling- material, like zinc oxyphosphate cement or gutta-percha. 

Galvanic shock is sometimes experienced when some other metal having 
a higher or lower potential than the amalgam filling comes in contact with 
it, as, for instance, a gold filling in an opposite tooth when contact is made 
and broken during mastication, or when a table fork touches it. 

As soon as the external surface of the filling becomes discolored gal- 
vanic shock ceases. This is due to the interposition of the metallic sul- 
phides, which are non-conductors of electric currents. 

Chemical Relations. — It has never been positively demonstrated that 
amalgam exercises any specific therapeutic influence upon the dentin, 
although clinical evidence is abundant that such is the fact with those that 
contain copper. Miller, in experimenting with the various plastic filling- 
materials, as to their antiseptic properties and their retarding influence 
upon the growth of mouth bacteria, found that copper amalgam was the 
only one which possesses such qualities, and that it invariably manifested 
a retarding or preventive action upon the growth of bacteria. Fig. 448 
shows this action upon a gelatin plate. 



Fig. 448. 




An inoculated gelatin plate containing : a, pieces of oxyphosphate cement one day old ; 6, 
pieces of gold amalgam one day old ; c, pieces of an old copper amalgam filling, age unknown ; d, 
pieces of stained dentin from a tooth which had been filled many years previously with copper amal- 
gam. (Miller.) 



Weagant, in writing upon this subject, says, "Instead of having any 
injurious effect upon the teeth or surrounding tissues, it is decidedly bene- 
ficial to them, acting as an antiseptic or germ destroyer." 

Fletcher also maintains the same view. 

According to Tomes, the sulphide of copper formed by the action of the 
hydrogen sulphide of the mouth upon the copper of the amalgam is 
readily converted, on exposure to air and moisture, into copper sulphate ; 
hence it is almost certain that the latter is formed upon the exposed sur- 
face of the filling. Cupric sulphate is freely soluble, and therefore is likely 
to permeate the dentin by following the tubuli. Sulphides of the other 
metals are not so readily converted into soluble salts, and therefore do not 
penetrate the dentin so freely. 



314 



OPERATIVE DENTISTRY. 



Flagg believes there is a gradual formation of soluble salts of silver, 
tin, and copper, — these metals forming the usual constituents of dental 
alloys, — which being dissolved are taken up by the contiguous dentin, thus 
changing the relations existing between the filling and the dentin, and ren- 
dering them more in harmony with each other (" compatible"), and, " with 
its incorporated metallic salts, becomes so in affinity with the amalgam filling 
as to insure almost completely harmonious apposition of tooth bone and 
filling, cessation, practically, of decay, and recalcification (?) with metallic 
lustre of decalcified dentin." 

Cadmium amalgam and amalgams which contain cadmium gradually 
soften and disintegrate, and if the cadmium is present in large quantity, 
the dentin becomes decalcified and stained a bright orange-yellow from the 
formation of cadmium sulphide. 

Dental amalgams, as a class, are, however, chemically, practically in- 
soluble in the secretions of the mouth. Lactic acid and the other less 
common solvent agents found in the mouth have little or no effect upon 
them. 

COMPOSITION OF ALLOYS. 

The metals which are used in the manufacture of dental alloys are 
antimony, aluminum, bismuth, cadmium, copper, gold, platinum, palla- 
dium, and zinc. 

The following condensed table gives the composition of a few of the 
best- known dental alloys. 





H 


> 
35 


•6 
o 

o 


a 

3 


ft 
ft 
o 
o 


a 

5 


o 

a 
< 






48.48 

46 

42.5 

43.35 

58 

60 

60 

48.24 

40 
50 
50 














51.90 

57.5 

50.35 

37 

35 

35 

49.27 

40.60 

40 

40 

50 


1.70 


.40 


















3.35 
5 


1.30 


1.65 
















5 








5 

0.05 
4.40 
20 




3 
2.44 
















3 


































1 







Antimony. {Stibium. Symbol, Sb. Fuses at 840° F.) — This metal has 
but little place in the manufacture of dental alloys. It is still used, how- 
ever, in a few of the alloys offered for sale, sometimes in large quantities. 

Amalgams containing antimony in considerable quantity are notably 
fine grained, very plastic, and do not shrink, but are exceedingly dirty to 
work. 

Small quantities of antimony added to silver-tin alloys, — tin in excess, 
— it is claimed, control the shrinkage. 

Aluminum. {Aluminum. Symbol, Al. Fusing-point, 1292° F.) — This 
is the lightest of the known metals, its specific gravity being 2.50 to 2.67. 
When alloyed with silver and copper it gives a non-tarnishing and non- 



PLASTIC FILLING-MATERIALS. 315 

corrosive quality to these metals and greatly increases their tensile 
strength. (Mitchell.) 

Aluminum has been used as a constituent of dental alloys for the pur- 
pose of controlling the color and imparting greater tensile strength, but it 
destroys the integrity of the amalgam. Black found that the addition of 
five per cent, of aluminum to sixty-five of silver, and thirty-five of tin 
formed an alloy that when mixed with mercury "amalgamated nicely, 
forming a very white, soft mass, but it soon became too hot to handle." 
The thermometer indicated 186° F. The setting was also attended with 
the formation of considerable heat and enormous expansion, and later 
disintegration of the mass took place, resulting in the formation of a dark 
powder which would cohere a little on being pressed together. 

Disintegration did not take place when the mass was rapidly worked 
and packed in glass tubes, but the tubes soon became too hot to handle. 
A remarkable phenomenon is observed during the combining of the alloy 
with the mercury, — viz., the evolution of gas, which gave off a distinct 
crepitating sound from the bursting gas-bubbles. The instruments used in 
packing the amalgam were darkened and corroded. 

The expansion of the material seems to be almost continuous, for Black 
states "that in twenty-four hours an expansion of one hundred and twenty 
points had occurred, as indicated by the micrometer ; at the end of the 
second clay the expansion reached one hundred and eighty-one points ; and 
at the end of the third day two hundred and seventeen rjoints, and though 
diminishing it did not stop. At the end of forty-three days it had reached 
the enormous figure of four hundred and forty-five points of expansion, 
when it passed beyond the capacity of the micrometer to register. 

"Annealing the alloys at 130° F. controlled the expansion somewhat, — 
it was stationary from the second day to about the fifth day, when it again 
began, slowly, and continued for about forty days." 

Aluminum, therefore, should have no place as a constituent of dental 
alloys, as its use not only destroys the value of the metals with which it is 
combined, but the added danger is to be considered of fracturing or burst- 
ing the thin walls of the cavity by the enormous expansion which takes 
place during the process of setting and afterwards. 

Bismuth. (Bismuthum. Symbol, Bi. Fusing-point, 507° F.)— This 
metal has been used in dental alloys to control the shrinkage in the low- 
grade silver- tin alloys, in which the tin is largely in excess of the silver, 
as it expands very considerably on cooling. 

Alloys containing bismuth amalgamate with great readiness and with less 
mercury. Amalgams made from alloys containing bismuth are very dark. 

Dr. Black found the expansion-shrinkage range reduced in those amal- 
gams which contained it, but the flow was increased. 

Cadmium. {Cadmium. Symbol, Cd. Fusing-point, 442° F.)— The use 
of alloys containing cadmium was first suggested nearly fifty years ago by 
the late Dr. Evans, of Paris. It was claimed for this metal that it amal- 
gamated readily, that it did not discolor, and that it set very rapidly, and 
made a durable filling. The hopes raised by these claims were soon dissi- 
pated, however, for gradual softening and disintegration of the mass took 



316 OPERATIVE DENTISTRY. 

place, the dentin was decalcified and stained a bright orange-yellow ; but 
worst of all, the pulps of many of the teeth filled with this material 
were devitalized from the poisonous — irritating — effect of the cadmium 
sulphide, and which is stained yellow by the action of sulphuretted 
hydrogen. Cadmium is still used as an occasional component of dental 
alloys, being introduced in the proportion of from one to three per cent. 
It is claimed by those using it that it causes more ready amalgamation, 
controls discoloration, and increases the rapidity of the process of setting. 
Even this small quantity, nevertheless, would seem to be out of place, for 
all of the above advantages can be obtained by more satisfactory and less 
objectionable means. 

Dr. Black found ' ' by the addition of five per cent, of cadmium to 61. 75 
per cent, of silver and 33.25 of tin that it greatly increased the expansion 
of the amalgam ; that it requires a large amount of mercury to amalgamate 
it ; that it sets very quickly, and makes very white and beautiful-looking 
fillings. 

' ' The expansion of the unannealed alloy was one hundred points in five 
days. Annealing largely controlled the expansion, reducing it to five 
points. In the expansion, the mass, if the walls of the cavity are smooth, 
slips squarely up and remains flat upon the top. 

"The flow in the unannealed alloy was 6.40; in the annealed, 3.54. 
The crushing strength was increased by annealing from two hundred 
and twenty-five to two hundred and ninety pounds." 

Copper. {Cuprum. Symbol, Cu. Fusing-point, 1996° F.) — This metal 
in small quantities enters into the composition of all of the better class of 
dental alloys. An addition of five per cent, to the silver-tin alloys — 
tin in excess — increases the rapidity with which it sets, controls the 
shrinkage, gives a white color to the amalgam, increases its hardness, 
and exerts — by reason of the formation of sulphide of copper, which 
on becoming oxidized forms the sulphate — an antiseptic action upon 
the dentin. 

Dr. Black found that five per cent, of copper added to the 61.75 of 
silver and 33.35 of tin alloy caused the unannealed alloy to set very 
quickly. When annealed it set as slowly as the unmodified alloy. 

The expansion and the expansion-shrinkage range was greatly in- 
creased, the flow was diminished, and the crushing stress was raised 
to the highest in the series. 

Copper Amalgam. — This substance is a combination of pure copper 
and mercury in varying quantities, and is therefore a binary amalgam. It 
is made by several processes : 

(1) By adding freshly precipitated and washed metallic copper to an 
excess of mercury ; as soon as solution of the copper is complete, the sur- 
plus mercury should be expressed by wringing the mass in a piece of 
chamois-skin, The plastic material remaining should then be formed into 
small tablets by pressing in suitable moulds ; when hardened it is ready 
for future use. 

Bollins, Ames, and others have published methods for making it by 
electrolysis. 



PLASTIC FILLING-MATERIALS. 317 

(2) Bollins's method is as follows : 

Distilled water, five gallons ; sulphate of copper, enough to saturate ; 
sulphuric acid, one pound. Mix, filter, and pour into a wooden firkin 
with wooden hoops. All of the chemicals should be absolutely pure. 
Place ten pounds of pure mercury in a glass jar and immerse in the copper 
solution. To the zinc plate of a galvanic battery attach a gutta-percha- 
covered wire, having one end bare for about an inch. This exposed end 
is to be immersed below the level of the surface of the mercury. Tie 
granulated pure copper in a bag and hang it in the copper solution, con- 
necting with a wire to the carbon of the battery. The battery is to be 
kept in action till the mercury has absorbed enough copper to make a 
thick paste. Then remove and wash thoroughly in hot water till all of the 
sulphate solution has been removed. Squeeze out the softer amalgam and 
allow the remainder to harden ; heat it and renew the squeezing as before. 
This method insures an amalgam of perfect purity, and is simpler than any 
of the old and faulty methods in use. 

(3) Chandler suggested another method of making copper amalgam, 
which is as follows : 

To a hot solution of sulphate of copper add a little hydrochloric acid 
and a few sticks of zinc, and boil for about a minute. The copper will be 
precipitated in a spongy mass. Take out the zinc, pour off the liquid, and 
wash the copper thoroughly with hot water. Pour on the mass a little dilute 
nitrate of mercury, which will instantly cover every particle of copper 
with a coating of the mercury. Add mercury two or three times the 
weight of the copper, triturate slightly in a mortar, and finish by heating 
the mixture a few minutes in a crucible. 

Copper amalgam is prepared for introduction into the cavity of a tooth by 
heating one of the prepared and hardened tablets, crushing and grinding 
it in a mortar, when it again becomes plastic. It may be made to set 
quickly or slowly as desired by squeezing out a portion of the mercury or 
by adding to it. On setting it becomes very hard, — in fact, it is the hardest 
of all the dental amalgams. It neither shrinks nor expands, retains good 
margins, and when properly made does not waste in the mouth. Its most 
objectionable feature is the black discoloration of its surface ; but this 
does not appear so objectionable if the surfaces of the fillings have been 
nicely polished, for then the surface has a black polish instead of the 
rough, dirty black color that prevails if the surfaces are left in a rough 
state. 

This material has no equal for filling the posterior teeth of children 
under twelve years of age, where antiseptic qualities are needed. Its 
greatest value, however, lies in its use in the deciduous molars of little 
children for whom rapid operations are a necessity. 

Copper amalgam was the only alloy tested by Dr. Black which did 
not flow under stress. It suffers no change of form under stress, except to 
crush into fragments. It is as rigid and unyielding within the limits of its 
strength as a piece of hardened steel, and can neither be bent nor com- 
pressed. ~No shrinkage during setting could be discovered. A very slight 
expansion was always present, but it was so slight as to be of no impor- 



318 OPERATIVE DENTISTRY. 

tance. In the large majority of the fillings which he tested it did not ex- 
ceed too(5tt of an inch. 

When it is once adapted to the walls of the cavity and hardened the 
adaptation is permanent, for it can suffer no change of form from the stress 
of mastication. These physical properties of copper amalgam give it 
permanence, and according to the opinion of Dr. Black, explain the power 
of the material to arrest caries rather than any chemical or disinfectant 
property of the copper or of its salts. 

Copper amalgam fillings, when well placed in properly prepared cavi- 
ties, retain their perfect margins, and do not discolor the tooth -structure ; 
and but for the wasting which sometimes occurs at the exposed surface 
and its dark color, this material would be the most satisfactory of all of 
the amalgams. 

Gold. (Aurum,. Symbol, Au. Fusing-point, 2016° F.) — This metal 
during late years has become, in small quantities, a quite common com- 
ponent of most of the high grade dental alloys. It enters into these alloys 
in the proportion of from three to five per cent. Experiment has demon- 
strated that more than any other metal used, in proportion to the small 
amount required, except copper, it diminishes shrinkage, increases the 
rapidity of setting, controls the color, adds to its crushing strength, and 
imparts fine grain while in the plastic state. The addition of from five to 
seven per cent of gold to the silver- tin alloys — silver in excess — gives the 
best results. 

According to Dr. Black, the addition of five per cent, of gold seems to 
give a little softer working property to the amalgam and slows the setting. 

Annealing increases the soft working property. It requires a little less 
mercury than the unmodified alloy, and the flow was slightly increased. 
This amalgam is very tough and bears a heavy crushing stress before break- 
ing, and it controls the shrinkage-expansion range, three points. 

Palladium. (Palladium. Symbol, Pd. Fusing-point, a little below that 
of platinum, about 3500° F., but requires the oxyhydrogen blow-pipe to fuse 
it.) — Palladium in combination with mercury forms a compound or binary 
amalgam, which has been recommended for use in the posterior teeth of 
children. It is made by combining palladium with three times its weight 
of mercury. Palladium is precipitated from a solution of its chloride by 
iron or zinc washed in nitric acid and dried. To this precipitate the 
mercury is added. Care is necessary in the mixing, as palladium forms a 
true chemical compound with mercury, and the action is so intense and 
the evolution of the heat so great that under certain circumstances an ex- 
plosion might take place. Palladium amalgam turns black upon the ex- 
ternal surface, but it does not discolor the dentin. It sets so rapidly that 
unless it is mixed very soft it becomes hard before it can be introduced 
into i:he cavity, consequently it should be worked rapidly and with warm 
instruments. Chandler found that the adding of a large proportion of gold 
rendered the palladium amalgam more tractable. 

It has no good qualities which are not possessed m a higher degree by 
copper amalgam. The only thing in its favor is its name, as it is one of 
the precious metals. 



PLASTIC FILLING-MATERIALS. 319 

Platinum. (Platinum. Symbol, Pt. Fusing-point, above 3500° F., and 
requires the oxyhydrogen blowpipe.) — According to Essig, platinum is 
only of value in an amalgam when combined with tin, silver, and gold 
in a proper proportion of mercury. Fletcher claims that the addition of 
a small quantity of platinum to a three-metal alloy, forty silver, sixty tin, 
ten gold, causes it to set quickly. 

Flagg looks upon platinum as having no value in a dental alloy over 
the same equivalent of tin, and therefore valueless as a component of amal- 
gams for filling teeth. 

Black found by adding five per cent, of platinum to the silver-tin alloy 
it made a dirty working amalgam, which blackened the hands, set slowly, 
flowed badly, and increased the shrinkage-expansion range. 

Silver. (Argentum. Symbol, Ag. Fusing-point, 1873° F.) — This is the 
most valuable and important of all the metals which enter into the compo- 
sition of dental alloys. In the superior grades of alloys it forms the largest 
portion, while in the inferior grades tin holds the first place. 

Silver is essential to the proper setting of an amalgam. Alloys in 
which silver predominates set much more rapidly than those in which tin 
forms the largest proportion. 

Alloys containing a large proportion of silver expand, while those com- 
posed largely of tin shrink. When silver and tin are united in the proper 
proportions they will make an amalgam having the lowest shrinkage- 
expansion range possible with any other known metals, except copper 
amalgams. This formula has been demonstrated by Dr. Black to be, sil- 
ver, 65 ; tin, 35 ; which gave shrinkage, ; expansion, 1. 

Tin. (Stannum. Symbol, Sn. Fusing-point, 442° F.) — This metal oc- 
cupies the next most important place to silver as a component of dental 
alloys. It shrinks in cooling more than any of the other metals which enter 
into these compounds. Amalgams which contain an excess of tin shrink 
badly, set slowly, and lack hardness. These objectionable features are 
overcome by combining it with silver or with silver and copper or silver 
and gold. The advantages of tin in a dental alloy are that it facilitates 
amalgamation, aids in producing a good color, and reduces conductivity. 

Zinc. (Zincum. Symbol, Zn. Fusing-point, 773° F.) — This metal in 
combination with copper formed one of the most ancient alloys of which 
there is any record. When added to dental alloys in which tin predomi- 
nates in large quantity, in the amount of one to one and one-half per cent., 
it completely controls the shrinkage, adds a satisfactory whiteness to the 
filling, and prevents discoloration. (Flagg.) 

Black found the addition of five per cent, to the 61.75 silver, 33.25 tin, 
formula greatly hastened the setting, and that it required more mercury 
for amalgamation ; but that the flow was decidedly decreased, the expan- 
sion range increased, and the crushing strength above the average. 

MAKING DENTAL ALLOYS. 

The rational method of making dental alloys is to melt that metal first 
which fuses at the lowest degree of heat. Tin, which forms a considerable 
part of all dental alloys, fuses at 442° F. This is the lowest fusing metal 



320 OPERATIVE DENTISTRY. 

that enters into their composition, and should therefore be melted first, 
and the other higher fusing metals added in the order of their fusing-point, 
as, for instance, in a binary alloy the silver, which melts at 1875° F., 
should be added to the melted tin ; in a ternary alloy the copper, which 
fuses at 1996° F., should be added after the silver ; and in a quarternary 
alloy the gold, which fuses at 2016° F., should be added after the copper, etc. 

The object of thus reversing the old method was to prevent the volatili- 
zation of the tin and thereby secure a definite compound, which was not 
the case when the tin was heated to more than 2000° F., as volatilization 
immediately takes place and an indefinite compound is the result. 

The practitioner who would make his own alloys should provide him- 
self with a good Hessian or sand crucible, holding ten or twelve ounces 
liquid measure, a pair of crucible tongs, and a quantity of borax to be 
used as a flux. 

Tin may be obtained at any hardware shop in the form of bars or 
ingots. Banca tin is the best, as being most free from impurities. 

Silver can be obtained of any silversmith. Granulated silver is the 
best for the purpose, as it is divided into small beads or granules, and is 
therefore dissolved more rapidly in the melted tin than larger pieces 
would be. 

Copper can also be obtained at the hardware shop. Soft copper wire is 
the best form in which to buy it. This should be cut into very small 
pieces, about one-eighth of an inch in length. 

Gold in the form of foil scraps is always on hand in the office of every 
dentist. 

The other metals which sometimes enter into the composition of dental 
alloys are easily obtained, if it is desired to experiment with them ; but 
tin, silver, copper, and gold are the only metals that are used in a really 
first-class alloy. 

Flagg, in describing a " melt," says the crucible should contain a liberal 
amount of borax, which should be melted first, filling it about one-third 
full. "This is intended for a ' flux.' An ordinary coke or coal fire is all 
that is required for the ' melt ;' but it is, of course, more systematically 
and perhaps more readily done in the usual dental or smelting forge -fire. 

" Having perfectly fused the borax, in it the tin is melted first, requiring 
but a low temperature, and after it is melted the granulated silver is added. 
These two metals are thoroughly stirred together with an iron rod or clay 
pipe-stem of suitable size and length, and when completely incorporated 
the copper— small pieces of wire — is added. This, like the silver, is soon 
melted, and may be equally homogeneously mixed. Lastly the gold is added, 
melted, and all is thoroughly stirred together with the iron rod or pipe-stem. 

1 c When perfectly melted and mixed, the fused mass should be quickly 
poured into a broad, open, flat, shallow matrix made of iron or soapstone : 
this favors prompt cooling, and thus secures the greatest uniformity of 
distribution to the components." 

After the ingot has cooled it can be reduced to fine grains or coarse 
powder by filing, or the ingots may be cast in round bars or rods, and 
reduced to fine shavings by turning in a lathe. 



CHAPTER XX. 

MANIPULATION AND INTRODUCTION OF PLASTIC FILLING-MATEKIALS. 

Amalgam is generally used under those conditions and circumstances 
in which a permanent filling is desired, but in which gold or tin and 
their combinations are inadmissible, either from the inaccessibility of the 
cavity, the frail condition of the tooth, the physical state of the patient, 
forbidding the nervous strain of long and tedious gold operations, or the 
inability of the individual to pay for such expensive service. Under no 
conditions, however, should amalgam be used in the anterior teeth. It 
may be used in some cases upon the distal surface of the first bicuspids, 
but never in a more anterior position. If the conditions require the use 
of plastics in the anterior teeth, the oxyphosphate cements and gutta- 
percha are the best for this purpose. 

Gutta-percha in the form of Hill's stopping is the most reliable of the 
plastics that are admissible in the anterior teeth. 

Amalgams, however, are not used to the same extent as they once 
were ; for many teeth that were formerly restored to normal contour by 
extensive operations with amalgam can now, since the introduction of the 
more advanced methods of crowning, be better and more permanently 
treated by these methods. 

Various combinations of filling- materials have also been resorted to, in 
order to limit the uses of amalgam as far as possible to those positions in 
which they would he unobserved, to prevent discoloration of the tooth 
substance, or to give added beauty, strength, and durability to such fill- 
ings as were subjected to great stress ; as, for instance, in compound cavi- 
ties in the bicuspids and molars, when the cervical portion of a filling is 
made of amalgam and the morsal portion of gold. 

The preparation of cavities for the reception of amalgams requires 
the same care and thoroughness in all of its details as would be observed 
in preparing them for gold fillings, the only difference being that retain- 
ing grooves and pits are not necessary to aid in the permanent anchorage 
of the filling, nor for starting it. If a general retentive form is given to 
the cavity, that is all that will be required to prevent its dislodgement 
under stress. Temporary separations are an essential preliminary step in 
the preparation of approximal cavities and in the restoration of contour 
in these locations. 

The Especial Uses of Amalgam. — 1. Amalgam is especially indi- 
cated in that class of cavities in which the cervical margin lies at some 
distance beneath the border of the gum, making it impossible from its 
inaccessibility and the difficulties in excluding moisture to successfully 
introduce gold. 

2. In large distal cavities in the second and third molars, where, by 

21 321 



32 



OPERATIVE DENTISTRY. 



reason of their location, their size and frail walls, or the physical condi- 
tion of the patient, gold fillings could not be satisfactorily placed. 

3. In large buccal cavities in the molars, which extend to the gum line 
or beneath. 

4. In large approximal cavities in bicuspids and molars. 

5. In large rnorsal cavities in the molars. 

6. In compound cavities involving the mesial, distal, buccal, or lingual 
surfaces united with the morsal. 

The last four classes of cavities can, of course, be successfully filled with 
gold, and usually with better results, than with amalgam ; but conditions 
and circumstances are often presented in which the operator is obliged to 
choose amalgam to the exclusion of the better material. 

The exclusion of moisture is as essential in the preparation and steriliza- 
tion of cavities to receive amalgam as when gold is to be used, and the 
rubber dam should be adjusted for this purpose whenever and wherever it 
is possible to do so. Because amalgam is a cheaper material, and requires 
less skill to manipulate it than gold, is no reason why its introduction 
should be less carefully and conscientiously performed, or less pains taken 
with the finishing of such a filling, than would be expended upon it if it 
were gold. Better results, no doubt, would be obtained in the use of amal- 
gam if a higher degree of care in details were expended upon it. 

The employment of matrices is often a necessity in filling large compound 
cavities in the molars when it is desired to restore the contour of the in- 

Fig. 449. 





Creager loop matrices. 



volved surfaces. In these cases the band matrix is the most serviceable, 
and to obtain the best results from its employment it should be permitted 
to remain until the amalgam has set sufficiently hard to allow it to be 
dressed to the desired form and polished. 

The ordinary loop matrix (Fig. 449) and the Guilford and Brophy 
matrices are not adapted to be left in the mouth by reason of their screw 
mechanism being in the way of the cheek. 

Dr. Herbst's method of forming a matrix to suit each individual case is 
admissible in this class of cases, for the reason that they are made in a 
moment, and can be so shaped that they will not injure the gum or the 
cheek, or interfere with the occlusion of the teeth ; consequently they may 



MANIPULATION AND INTRODUCTION OF PLASTIC FILLING-MATERIALS. 323 

be permitted to remain upon the tooth for several days if desired. They 
are made as follows : A strip of German silver, No. 33 gauge, is cut of such 
width as will reach from the gum to the morsal surface of the tooth, and 
of sufficient length to embrace it and have about one- fourth of an inch to 
spare. This strip is then passed around the tooth, and the ends grasped 
with a pair of Herbst pliers — any flat nose pliers will answer the purpose, 
however — and drawn tightly around the tooth by pinching the ends to- 
gether. A close adaptation of the band to the tooth is thus secured. 
While still holding the ends of the band with the pliers it is removed 
from the tooth, and the ends soldered together over an alcohol flame or a 
Bunsen burner with tinner's solder. The matrix is then replaced upon 
the tooth, and if it impinges upon the gum or interferes with the occlusion 
of the teeth, it is again removed and trimmed with small curved scissors 
to suit the requirements of the case, when it is again replaced after the 
rubber dam has been adjusted. 

If the band does not fit properly at the cervico-approximal border, it 
can be brought to position by the insertion of a wooden wedge. On the 
removal of the matrix, which should not be done until the amalgam has 
set, the filling can be shaped and polished as though it were gold. 

Mixing Amalgams. — The proper mixing of amalgams is an important 
factor in the "shrinkage-expansion range" and in the u flow" of the 
mass, as shown by Dr. Black. Amalgams in which the alloy has been well 
incorporated with the mercury, or in which the mercury has been evenly 
distributed, shrink or expand less — heavily tinned amalgams shrink ; 
heavily silver amalgams expand — than when they are insufficiently mixed 
or the mercury is unevenly distributed. The flow is likewise decreased by 
an even distribution of the mercury. 

Alloys made of metals which fuse at a comparatively low degree of 
heat, or alloys in which these metals predominate, require less mercury to 
dissolve the particles of the alloy and to form a plastic mass than do those 
made of metals which fuse at a considerably higher degree of heat. The 
silver-tin alloys — tin predominating — require less mercury to form a plastic 
workable mass than the same binary alloy in which the silver is in excess. 

Flagg and Fletcher both recommend the xoeighing of the alloy and the mer- 
cury for every u mix." Flagg' s submarine alloy, which is composed of 
silver 60, tin 35, copper 5, requires from forty-six to forty-eight per 
cent, of mercury to make a workable mass. 

Flagg's contour alloy, containing silver 58, tin 37, gold 5, and other 
alloys of this grade require from forty-eight to fifty per cent, of mercury 
for perfect amalgamation, while those containing tin CO, silver 40, require 
only from thirty-seven to thirty-nine per cent., and those composed of 
tin GO, silver 35, gold 5, from forty-one to forty-three per cent, of 
mercury. 

If the operator knows the exact formula of the alloy which he is using, 
the proportion of mercury necessary to completely amalgamate the alloy 
is readily determined by the above. If, however, he does not possess the 
formula, he can ascertain by an experimental "mix" the amount of mer- 
cury necessary to obtain the best results in working any grade of amalgam. 



324 



OPERATIVE DENTISTRY. 



The amount of mercury required for the amalgamation of dental alloys 
is greatly increased as the amount of silver passes beyond sixty per cent.j 
so that with an alloy containing seventy per cent, of silver it was very 
difficult to form a workable mass with fifty per cent, of mercury ; while 
with eighty per cent, of silver it becomes necessary to use as much as 
sixty per cent, of mercury. 

In mixing amalgams by weight, the amount of the alloy necessary for 
the case in hand should first be weighed, and then the exact proportion by 
weight of mercury added to it. These should be placed in a mortar and 

Fig. 450. 




Flagg watering pliers. 



Fig. 451. 



mixed with the pestle until the mercury is thoroughly incorporated, 
mating an even mass of firm consistency. It is then taken in the palm of 
the hand and kneaded into a mass, and compressed in a piece of chamois- 
skin or silk fabric, by wringing with 
the fingers or with a pair of flat-nosed 
pliers, or with Flagg' s wafering pliers, 
shown in Fig. 450. 

If the u mix" has been properly 
proportioned, no mercury can be ex- 
pressed by gentle pressure with the 
pliers, and but very little under severe 
pressure. The practice of adding 
more mercury than is needed in mix- 
ing an amalgam, and then expressing 
it in order to obtain a good working 
mass, is to be deprecated, from the 
fact that the mercury is the solvent 
or fusing element in the amalgam, and 
whenever any portion of it is taken 
from the mass, by just that much the 
composition of the amalgam is altered and its physical characteristics 
changed. 

Dr. Black advocates the plan of mixing the amalgam in the hand until 
a. fairly even distribution of the mercury is secured, as by this method his 
experiments showed that the strongest amalgam was secured. He found 
also that u any form of violence weakens the product" either in mixing, ex- 
pressing the excess of mercury by compression with a vice, or by undue 
manipulation in packing it into the cavity. 

Mixing amalgams in the hand is a dirty process, which discolors the 
hand and the fingers with the metallic oxides. To overcome this difficulty 




Glass mortar and pestle. 



MANIPULATION AND INTRODUCTION OF PLASTIC FILLING-MATERIALS. 325 

Dr. Genese invented a rubber mortar to be held in the hand, the finger 
used in the mixing to be covered with a rubber finger-stall. 

Fletcher's method of mixing is to place the weighed proportions of 
alloy and mercury in a long glass tube and then violently shake it until 
amalgamation takes place. 

The writer prefers to mix amalgams by placing the desired amount of 
alloy in a mortar (Fig. 451) and adding the mercury little by little while 
the mass is being triturated, until a rather dry, crumbly mass is formed ; it 
is then turned into the palm of the hand and kneeded with the index-finger 
for a little time, when from the heat imparted to it from the hand it be- 
comes softer, and can be worked into a mass that will hold together. It is 
then placed in a napkin and compressed into a compact mass by wringing 
and squeezing between the thumb and finger, and afterwards cut into cubes 
of suitable size for the case in hand. This forms a mass which works 
easily and without the appearance of an excess of mercury upon the sur- 
face of the filling during the operation of packing it into the cavity. 

Washing Amalgams. — The idea of washing amalgams originated in 
the fact that alloys that had been cut for some time became oxidized upon 
the surface, and it was thought caused discoloration of the filling. It 
was believed that these oxides could be removed by washing in alcohol or 
other fluids and thus prevent discoloration. 

The real value of washing amalgams is, however, still a mooted ques- 
tion in the profession. Flagg believed that "washing" increased the 
tendency of the filling to shrink. Fletcher demonstrated that "washing" 
was absolutely detrimental, as it greatly facilitated and increased shrink- 
age. Burchard * recommends washing the amalgam in spirits of chloro- 
form, as it has been observed that washed amalgams retain their color 
better. The writer has never been able to discover any difference in the 
maintenance of color between washed and unwashed amalgams, and he has 
experimented very considerably in this line and has carefully observed the 
results in the mouth. 

The composition of the amalgam and the finish given to the filling are 
the main factors in controlling the tendency to discoloration. 

INTRODUCTION OF THE AMALGAM. 

The cavity having been prepared, the rubber dam adjusted, and the 
surface of the dentin dried and sterilized, the tooth is ready to receive the 
filling. The amalgam should be introduced into the cavity in small pieces. 
The first piece should be large enough to cover the bottom of the cavity 
when it is packed into place. The packing should always be done by 
hand-pressure. Another piece is then added to this and pressed into 
position with suitable instruments, and the filling built up layer after layer 
until the cavity is full. 

Various instruments have been devised for carrying the amalgam to 
the cavity besides the ordinary curved pliers. Fig. 452 represents an 
instrument for this purpose, which has one end armed with coarse serra- 

* American Text-Book of Operative Dentistry. 



320 



OPERATIVE DENTISTRY. 



tions into which amalgam has been packed and permitted to harden. This 
produces a surface which will, by affinity or attraction, pick up small 
pieces of amalgam and hold them until they are deposited in the cavity. 

Other efficient instruments are shown in Fig. 453. These are of equal 
value in carrying the amalgam to cavities in the teeth of the upper and 
lower jaws. 

Fig. 452. 



Loadstone amalgam -carrier. 

For packing the amalgam into the cavity and shaping the filling there 
are no better instruments than those shown in Figs. 454, 455, and 456. 

Fig. 453. 




Amalgam-carriers. 



Packing and Condensing. — Several methods have been recommended 
for packing and condensing the amalgam, — viz., by burnishing, pressing, 
and tamping. 

Fig. 454. 




Dr. J. Foster Flagg's amalgam-instruments. 



Burnishing the amalgam into place is the method most commonly fol- 
lowed, and it is claimed for this method that a better adaptation of the 
material to the cavity walls is obtained than by any other. Dr. Black has 
shown that "severe burnishing makes a weak filling." 

Pressure, steady and light, has, according to the same investigator, 
given the best results in his experiments upon the manipulation of amal- 
gams. Strong pressure, while bringing free mercury to the surface,— which 



MANIPULATION AND INTRODUCTION OF PLASTIC FILLING-MATERIALS. 327 



the cavity, if done moderately, gave about the same results. 

Tamping or tapping the amalgam into position is a method which was 
introduced by Dr. Flagg, and is described as follows : " Tamping consists 
of delivering light blows, from the appropriate filling- instruments, upon 
the amalgam after it has been crushed into approximate position and apposi- 
tion. This 'tamping' is not to be done with the mallet, either hand, 
automatic, or electric, as a different kind of blow from any so given is far 



Fig. 455. 



Fig. 456. 




Kirk's universal Revised set of amalgam-instruments, 

approximal instru- 
ments for plastics. 

preferable. Tamping is a mingled push and blow, which is soon acquired, 
and is as promptly recognized as very efficient in producing admirable 
results." The writer has followed this method for many years, and has 
never seen any good reason for changing to another. 

Wafering. — As the filling nears completion many operators are in the 
habit of finishing it with "wafers" of hard amalgam, after the manner 
suggested by Flagg. These wafers are made by compressing a portion of 
amalgam — either from the mix then being used or of a higher grade alloy 
— in chamois, with a pair of strong pliers, until all the mercury possible 
is expressed from it. The process of wafering hastens the setting of the 
amalgam and facilitates the final finishing. 

Lining. — In large cavities having thin walls it often becomes necessary 
to "line" the cavity, in order to give them the needed support and to 
prevent discoloration from the bluish appearance of the amalgam showing 
through the enamel, or from discoloration caused by the formation of sul- 
phides and oxides of the metals contained in the amalgam. 

The materials generally used for this purpose are the zinc oxychloride 
and oxyphosphate cements. 

In lining cavities, the cement should never be allowed to rest in contact 
with the enamel margins. The margins should always be free from the 
cement, so that the amalgam may be in perfect contact with them through- 
out their whole extent. If for any reason the cement is allowed to remain 
in contact with the enamel margins, and the amalgam makes contact with 
that instead of the enamel, failure of the filling is bound to result by the 
washing away of the cement and opening the cavity to the agencies of caries. 



328 OPERATIVE DENTISTRY. 

Two methods of lining are employed : one is to partially fill the cavity 
with the cement and allow it to become thoroughly hardened, and then to 
prepare it for the amalgam filling by removing the cement from the enamel 
margins, and give a retentive shape by undercuts in the base of the cement. 
Another method is to line the cavity with rather soft cement, care being 
taken to keep the enamel margins free, and while the cement is yet soft 
to introduce the amalgam, rubbing it into the surface of the cement. It 
is claimed for this method that by introducing the amalgam while the 
cement is in a plastic state it adheres to the enamel and renders retentive 
shaping unnecessary. 

Guarding. — In large cavities in the approximal surfaces of the bicus- 
pids and molars which extend beneath the gums, it becomes necessary to 
introduce a filling-material which by reason of its physical character and 
antiseptic action will conserve the tooth-structure. Flagg describes 
"guarding" as "placing a material in apposition with the cervical wall 
of a cavity of decay, which shall, by its possession of certain physical 
characteristics, act under certain 'law,' to prevent, in greatest degree, the 
recurrence of decay at that 'vulnerable spot.' " 

Tin-foil is generally used for this purpose under gold fillings, while 
some operators use amalgam. 

In guarding the cervical margin under amalgam fillings, alloys are used 
which contain copper and a high -per cent, of silver. For this purpose 
there is no alloy better than Flagg' s "submarine," composed of silver, 
GO ; tin, 35 ; copper, 5. 

Copper amalgam may also be used for the same purpose, and some 
operators prefer it. 

Guarding with amalgams is usually employed in those cases in which 
caries has extended so far beneath the gum as to make it impossible to 
keep the cavity dry by adjusting the rubber dam. Under such circum- 
stances, after the cavity has been prepared an antiseptic should be applied, 
and sealed into the cavity with a temporary stopping. On the next day, 
after adjusting a napkin to prevent the entrance of moisture, the dressing is 
removed, and the submarine amalgam, which had been previously prepared, 
should be rapidly introduced, packed into position with suitable instru- 
ments or pellets of bibulous paper, and built up to the gingival border, the 
balance of the cavity being filled with a temporary stopping. The surface 
of the amalgam should be smoothed and overhanging edges removed while 
it is in the plastic state, for after it has "set" it is cut with great difficulty. 
At a subsequent sitting the surface of the amalgam filling beneath the 
gum should be nicely finished, when the rubber dam may be adjusted, the 
temporary stopping removed, and the balance of the cavity filled with 
ordinary amalgam. The amalgam which is used for the bulk of the filling 
should be one which will maintain a good color. An alloy containing 
silver 60, tin 35, gold 5, will best subserve the purpose. 

It sometimes becomes necessary to complete the operation at one sitting. 
Under these circumstances, the rubber dam can be adjusted after the cer- 
vical section of the cavity has been filled and the operation completed. 
This method is, however, not so satisfactory as the other, because of the 



MANIPULATION AND INTRODUCTION OF PLASTIC FILLING-MATERIALS. 329 

danger of displacing the cervical section of the filling while the other is 
being packed into position, and the greater difficulty of perfectly finish- 
ing the cervical portion after the entire filling has been completed. 

Flagg recommends in all of those fillings which are located in surfaces 
of the teeth exposed to view, and where any discoloration would be objec- 
tionable, wafering such fillings with "facing" alloy, composed of, rela- 
tively, silver 57, tin 35, gold 5, zinc 3, as this gives a more acceptable color. 



COPPER AMALGAM. 

For the purpose of guarding and for submarine work in unexposed 
positions, and in the molar teeth of little children, some of whom will 
not tolerate the rubber dam or even a napkin, copper amalgam occupies a 
high position as a filling- material and a conserver of tooth-structure. 

Cavities prepared for this material require but slight retentive shaping 
to retain it in position. 

Fig. 457. 




Ebony cone-socket handle, 

In preparing copper amalgam for introduction into a cavity, a cube of 
the material is placed in an iron spoon (Fig. 457), or grasped with a pair 
of pliers, and held above an alcohol or Bunsen flame until the mercury 
shows itself in tiny globules upon the surface, when it is placed in a mor- 
tar, crushed and ground into a soft mass. 

The cavity, when possible, should be protected from moisture by adjust- 
ing a rubber dam or a napkin and sterilized. The amalgam is then intro- 
duced in small pieces, and packed by tamping or burnishing the material 
against the walls of the cavity until it is full. The surface of the filling 
may be smoothed with a broad spatula or by wiping with pellets of cotton. 

Large cavities may be advantageously filled or lined with zinc oxy- 
phosphate cement for the lower two-thirds or three-fourths of the cavity 
and the filling finished with amalgam. This practice, however, is im- 
peratively demanded in large and deep-seated cavities which have ex- 
tended nearly to the pulp, to guard against shock from thermal changes. 

By the aid of "Mack's" screws, set in the pulp-canals, the Herbst 
matrix, and a strong, quick-setting alloy — Flagg' s contour — large contour 
operations, like the building of a large section of, or the whole crown of, a 
molar, may be successfully accomplished, as shown in Figs. 458, 459, 460, 
and 461. It is important that the matrix fit the cervix of the tooth closely, 
and be so adjusted to the occlusion of the opposing teeth that the jaws can 
be closed- in a normal manner. After the cavity has been filled or the 



330 



OPERATIVE DENTISTRY. 



crown restored, the matrix should be allowed to remain for a few hours, 
or better, overnight, when the surfaces may be trimmed and shaped by 
filing and grinding. 

In packing the amalgam great care, for obvious reasons, should be 
exercised to secure perfect adaptation of the material to the walls of the 
matrix and the surfaces of the screws. 



Fig. 458. 



Fig. 459. 



Fig. 460. 



Fig. 461. 







Cavity prepared. 



Cavity filled. 



Cavity prepared. 



Crown restored. 



If the matrix has been carefully fitted to the cervix and the occlusion 
properly adjusted, there will be very little trimming and carving required 
to give proper form to the restored crown. 

Finishing. — The proper finishing of an amalgam filling is as important 
as the finishing of gold fillings. An imperfectly finished filling will, by 
the roughness of its surface, its ragged or overhanging edges, invite a re- 
currence of dental caries at the enamel margins by the retention of ferment- 
able material and the protection offered to the zymogenic bacteria, while 
fillings that are highly finished retain a better color, or, in other words, do 
not tarnish or oxidize so readily. 

The process of finishing amalgam fillings which have become hard by 
crystallization is so similar to the finishing of gold fillings that it is not 
necessary to describe it, as it would be only a reiteration of these methods. 



GUTTA-PERCHA. 

Gutta-percha was first introduced to the consideration of dental practi- 
tioners a little over fifty years ago (1847) as an admirable material for 
temporary fillings in frail teeth, on account of the ease with which it could 
be manipulated, its non-irritating and non-conducting qualities, its in- 
solubility in the fluids of the mouth, and its fair resistance to the attrition 
of mastication. Its color, dark brown, was so objectionable that it found 
little favor with the profession on this account. But upon the introduc- 
tion soon afterwards of a secret p reparation known as "Hill's stopping," 
which was white in color and possessed all of the advantages of the crude 
gum, it rapidly came into use for a temporary stopping. 

Its inventor, Dr. Hill, however, had very exalted views of its value, 
for he said, "Though I do not expect it to supersede gold entirely, yet I 
believe it can be advantageously substituted for that material in many 
instances." Although this opinion has never been generally concurred 
in by the profession, it was nevertheless the very best material for tempo- 
rary fillings that the dentist has ever had placed in his hands ; and, in fact, 



MANIPULATION AND INTRODUCTION OF PLASTIC FILLING-MATERIALS. 331 

it has proved in many instances, when introduced into cavities which by 
their position were not subject to the attrition of mastication, to be worthy 
to be classed as a permanent filling- material, for it has been known in such 
locations to have perfectly preserved the teeth so filled for from five to ten 
years, and even longer. With the death of Dr. Hill the manufacture of 
the "stopping" ceased, and although several alleged analyses of the 
material have been published, no one has ever been able to produce a 
substance that possessed all of the qualities of Hill's stopping. 

A formula which makes a very good substitute for it, and which, when 
published, was claimed to be identical with Hill's formula, is as follows : 

R Quicklime, 2 parts ; 
Quartz, 1 part ; 
Feldspar, 1 part. 

These are ground to an impalpable powder and mixed. Pure gutta- 
percha is then heated to a plastic state and the powder kneaded into it as 
long as it will receive it without becoming brittle. 

The white gutta-percha preparations of to-day are made in imitation of 
Hill's stopping, but they are only imitations to those of the older members of 
the profession who had any experience in the use of the original material. 

The gutta-percha preparations as manufactured at the present time are 
composed chiefly of gutta-percha and oxide of zinc, these materials being 
kneaded together — upon an iron or porcelain slab heated over boiling 
water — by the aid of a broad steel wedge-shaped instrument termed a 
kneader. The greatest care has to be exercised in its manufacture to 
prevent overheating (heat-rotting), as this spoils the material by destroy- 
ing its toughness and causing disintegration of the mass. 

Guttapercha as prepared for the use of the dentist is in three forms, 
— one, the well-known pink base-plate gutta-percha ; another, the white 
gutta-percha prepared in small cakes, sticks, or pellets ; and the third, a 
softer "temporary stopping" used for covering dressings. The white 
gutta-percha is prepared in three grades, — viz., "low heat," "medium," 
and "high heat." The "low heat" grade becomes sufficiently plastic for 
manipulation at temperatures ranging from 140° to 200° F. The "medium" 
grade is rendered of equal plasticity by a temperature ranging from 200° 
to 210° F. The "high heat" grade requires a temperature of from 216° 
to 230° F. to render it sufficiently plastic for manipulation, and is therefore 
more liable to be overheated and its integrity destroyed than are those 
which can be rendered plastic over hot or boiling water. Flagg thinks for 
this reason the medium grade of gutta-percha is the best for general use. 

Flagg' s formulae for the "low heat" and "medium" grades of gutta- 
percha are, " low heat," gutta-percha, one part ; oxide of zinc, four parts ; 
"medium," gutta-percha, one part; oxide of zinc, six to seven parts by 
weight. 

Physical Characteristics.— Gutta-percha stopping is the most bland 
and non-irritating filling-material known, and by its non-conducting prop- 
erties of both heat and electricity it becomes the most valuable filling- 
material for the temporary treatment of hypersensitive dentin and nearly 



332 OPERATIVE DENTISTRY. 

exposed pulps that the dentist has at his command. It is not acted upon 
by the fluids of the mouth, at least in any appreciable degree, while it is a 
notable fact that it maintains its integrity better in the fluids of the mouth 
than when exposed to the atmosphere. Softened gutta-percha pellets will 
unite with each other under pressure when the surfaces are dry, but they 
cannot be made to do so when wet. It contracts on cooling, so that it is 
almost impossible to make an absolutely moisture-tight plug ; in fact, very 
few fillings made out of the mouth will resist the "carmine test ;" and yet 
with this great fault its record as a " tooth-saver" is exceptionally good. 
It is susceptible of being colored to imitate any shade of the teeth. It is 
not so hard nor so rigid as the other filling-materials, but it has been no- 
ticed that its hardness increases with time when it has been properly intro- 
duced into a cavity that is protected from attrition. Gutta-percha fillings 
which soften and disintegrate in the mouth have been spoiled by "heat- 
rotting," either during the process of manufacture or in being prepared 
for introduction into the cavity. The pink base-plate gutta-percha assumes 
a polished surface, and seems to wear better when subjected to attrition 
than do the white varieties. 

Some operators prefer the pure gum to any other form, believing that 
its admixture with the substances that are used to harden and bleach it 
detract from its wearing qualities and only render it more destructible. 

Use of Gutta-Percha. — Gutta-percha is employed principally as a 
temporary filling in the deciduous and permanent teeth, for "sealing in" 
dressings, treating hypersensitive dentin, for the permanent filling of 
root-canals, for "guarding" oxyphosphate fillings, for capping or pro- 
tecting nearly exposed pulps, for permanent fillings in locations not ex- 
posed to attrition, and in badly broken-down teeth which are too frail to 
be filled with metallic stoppings. Dissolved in chloroform — chloro-percha 
— it is often used to line cavities which are to receive zinc oxychloride or 
zinc oxyphosphate cements, the object being to protect the pulp from irri- 
tation and pain which might be induced from the zinc chloride in the 
former and the glacial phosphoric acid in the latter. 

The form of gutta-percha known as " temporary stopping" is furnished 
in two colors, pink and white, and is used principally for "sealing in" 
dressings that have been placed in carious cavities to reduce hypersensi- 
tiveness or to destroy the vitality of the pulp y or for covering dressings 
that have been placed in the root-canals of devitalized teeth. On account 
of its extreme softness, however, it is not intended to subserve more than 
the most temporary purpose, although this feature makes it very valu- 
able, as it is easily and quickly introduced, and as easily and quickly 
removed. 

Many operators confine their use of the pink variety to covering arseni- 
cal applications and other dressings which the conditions of the tooth 
make imperative should be changed at the next sitting, while the white 
is used for those cases which are not urgent, or are being tested as to their 
fitness to receive a permanent filling. 

Gutta-percha which is prepared for filling the root-canals of devitalized 
teeth is made in the form of long slender cones or points, either by rolling 



MANIPULATION AND INTRODUCTION OF PLASTIC FILLING-MATERIALS. 333 

or cutting of proper size and form to be readily introduced into the 
canals. They may be prepared either from the pink base-plate gutta- 
percha or from the white variety. 

Gutta-percha by reason of its indestructibility, non-irritating character, 
ready adaptability, and ease of manipulation is the material par excellence 
for filling root-canals. 

For "guarding" zinc oxyphosphate fillings at the cervical margin it is of 
great value, for it prevents the dissolution of the cement which is so com- 
mon at this location, and thereby relieves the anxiety of the operator over 
the possibility of the oxyphosphate being undermined in a few months 
and the carious process re-established. In many individuals the oxyphos- 
phate cement wears well, even in positions exposed to the attrition of mas- 
tication, but is rapidly disintegrated at the cervical margins. By "guard- 
ing" with gutta-percha at these locations the durability and value of such 
fillings is greatly increased. 

As a capping for nearly exposed pulps gutta-percha of the "low heat" 
grade has no equal, its greatest value lying in its non-conducting quality, 
which protects the pulp from thermal shock. 

As a permanent filling in large cavities in the deciduous and permanent 
teeth not subjected to the friction of mastication, especially buccal cavi- 
ties in molars and simple labial or approximal cavities, the "high heat" 
grade may be depended upon to wear well and to protect from a recurrence 
of caries. It has its greatest usefulness in those cavities in which the 
carious process has penetrated to such depth as to nearly expose the pulp, — 
the pulp being first protected by a layer of the "low heat" grade, — and in 
devitalized teeth which have very frail cavity walls or are inclined to 
pericemental or apical irritation, and by reason of its non-irritating 
quality in all cavities which extend beneath the free margin of the gum. 
Many operators use it to the exclusion of all other filling-materials for 
stopping approximal cavities in the anterior permanent teeth of children 
under twelve to fourteen years of age. Fillings in these locations, if 
properly introduced, may be counted upon for doing good service for from 
five to eight years or longer. 

The pink base-plate gutta-percha wears better in all exposed surfaces 
than the white, but the white, by reason of its more harmonious color, 
should be invariably used in all cavities in the anterior part of the mouth. 

The pink base-plate is also a very serviceable material for maintaining a 
temporary separation of teeth which are to be filled with metallic stoppings, 
but in which the pericemental irritation induced by the separating pro- 
cess is so great as to make it necessary to postpone the operation to a later 
date. Or it may be used for gaining temporary separations between the 
bicuspids and molars preparatory to introducing contour fillings, by pack- 
ing the approximal cavities full of the material and allowing the force of 
mastication coming upon the fillings to gradually separate the teeth by the 
spreading of the material. 

Methods of Softening. — Upon the proper softening of the prepared gutta- 
percha stoppings depends their integrity and durability. The greatest of care 
should be exercised in softening gutta-percha that it be not overheated ; this 



334 



OPERATIVE DENTISTRY. 



caution cannot be emphasized too strongly, as the complaints so often made 
of gutta-percha u rotting" or disintegrating in the mouth are the result of 
overheating, or u heat- rotting," before introducing the filling, and not dis- 
integration of the material from the action of the oral secretions, as some 
have supposed. 

Permanent results cannot be obtained with gutta-percha — except by 
accident — when the material is heated by holding it in the flame of a lamp 
or Bunsen burner, as practised by so many operators, as by this method it 
is usually overheated, and as a result, when subjected to the influences of 
the oral secretions, softening and disintegration take place. 

Dr. Flagg some years ago invented the device shown in Fig. 462 for 
heating the various grades of gutta-percha and the packing instruments. 

It is composed of a lamp-stand, 
Fig. 462. which carries a small metal wa- 

ter-tank, upon the cover of which 
are arranged two shelves ; the 
upx^er one, which receives the 
least amount of heat, is intended 
for softening the "low heat" 
grade of gutta-percha, the lower 
one softening the " medium" 
grade, while the cover of the 
tank is utilized for heating the 
"high heat" grade and the pack- 
ing instruments, the handles of 
which rest upon a notched rack 
and the points upon the cover of 
the tank. Water is placed in 
the tank and heated to the boil- 
ing-point. Overheating of the 
various grades of the material becomes impossible by using this method 
of softening. 

Of late years there has been a demand upon the part of some operators 
for harder grades of gutta-percha, which require a degree of heat for their 
softening greater than can be obtained by boiling water. The therrnoscopic 
heater of Dr. "W. Storer How,* shown in Fig. 463, meets these require- 
ments in a most perfect and scientific manner. The heater is composed of 
a block of steatite, selected for its heat-retaining qualities and the desira- 
bility of its surface. At one end is a wooden handle, at the other end a 
circular recess, in the centre of which is a small disk, A, made of fusible 
metal which melts at 212° F. On the heater within the circular recess are 
placed a suitable number of gutta-percha pellets, as 1, 1, and the heater 
is held over the flame of a spirit-lamp or Bunsen burner until the disk 
of fusible metal is melted, when the gutta-percha will be sufficiently 
softened for introduction into the cavity. The heater will maintain 
the proper temperature long enough for the completion of an ordinary 




improved gutta-perc 
tool-heater. 



Dental Cosmos, vol. xxxiv. p. 2S1. 



MANIPULATION AND INTRODUCTION OF PLASTIC FILLING-MATERIALS. 335 

operation, but if the metal in the mean time loses its fluidity and thus 
indicates the lowering of the temperature, it can be restored by hold- 
ing the heater for a moment over the flame until the metal again becomes 
fluid. 

Fig. 463. 




Dr. How's thermoscopic heater. 



When the metal disk is fused the pellets 1, 1, will be at a temperature 
of about 212° F., while pellets at 2 would have a temperature of about 200° 
F., and those at 3 and 4 about 194° and 180° F. respectively. Disk B, 
which is made of fusible metal which melts at 230° F., is provided as a 
substitute for disk A, which may be melted and poured out, and B used in 
its stead. In this manner the "high heat" gutta-percha and the lower 
grades may be properly softened without the least degree of u heat- rotting" 
of the material. 

Manipulation of Gutta-Percha. — Instruments which are suitable for 
filling difficult and inaccessible cavities with gold are best adapted for 
packing gutta-percha, for, as a rule, the cavities in which this material 
is generally used are in difficult and inaccessible locations. In packing 
this material it is best to use warm instruments, as it is important that the 
whole mass of the filling be kept in a plastic state until perfect adaptation 
to the walls has been secured. 

The preparation of cavities to receive gutta-percha fillings, while re- 
quiring the thorough removal of all decalcified and infected dentin, should 
also be directed to the conservation of the enamel walls to the full limit 
of safety against fracture, especially in preparing approximal cavities in 
the incisors and cuspids. 

With an intact labial enamel wall, though it be transparent, gutta- 
percha can be so packed against it as to protect and strengthen it, and 
at the same time so restored in color as to defy detection except by close 
scrutiny. 

It is important in the introduction of gutta-percha that moisture be ex- 
cluded from the cavity. The rubber dam should therefore be adjusted, and 



336 OPERATIVE DENTISTRY. 

as much care taken in this respect as would be given to it if the cavity- 
were to be filled with gold. The cavity should next be dried and steril- 
ized, and again dried, after which the gutta-percha may be packed in 
place. This may be done by either one of two methods. 

The first method is by introducing the gutta-percha in small pellets 
into the cavity, — which has been previously warmed by a blast of heated 
air, — packing them first into the most inaccessible parts of the cavity, and 
finishing with a larger mass. 

The second method is to introduce a single large mass somewhat larger 
than the cavity, and with a broad spatula-like instrument, with a rocking 
motion work it into the cavity much as would be done in taking an im- 
pression of the part. 

Some operators prefer to line the cavity walls with oxychloride or 
oxyphosphate of zinc cement in those cases in which the walls are very 
thin and frail ; tinting these materials to match the color of the tooth, and 
after it has hardened to fill the balance of the cavity with gutta-percha 
after one of the above methods. 

Dr. How believes that the common method of introducing the filling in 
small pellets is responsible for leaky fillings. He says, " There is good 
reason for the belief that the common mode of successively introducing 
small pieces of perfectly softened gutta-percha into a comparatively cold 
cavity, and employing instrument points more or less heated for packing 
the cooled plastic against one side of the cavity after another, must in the 
nature of the case result in a leaky filling, such as gutta-percha is com- 
monly said to make, whereas the defect is due not to the material, but to 
its inconsiderate manipulation." Dr. How claims that by the "single 
mass" method perfectly moisture-tight plugs can be made, as demonstrated 
by him, such fillings successfully resisting the aniline-dye test after several 
days' immersion. 

Finishing Gutta-Percha Fillings. — Gutta-percha fillings which have 
been properly introduced need but little trimming or finishing. To hasten 
the hardening of the filling, a spatula which has been immersed in ice- 
water and quickly dried should be applied to the surface of the filling to 
abstract the heat, and as soon as it has been sufficiently cooled the over- 
lapping edges may be removed with Dr. Gordon White's sickle-shaped 
trimmers (Fig. 444) or those of Dr. E. K. Wedelstaedt. The surplus ma- 
terial should be shaved off in thin slices, never in large mass, as this effort 
would be likely to drag the filling away from the margins. The trimming 
should always be from the centre of the filling towards the circumference, 
for the same reason. The surface may be finished by a rapidly revolving 
cuttle-fish disk, or by wiping the surface of the filling with a tape mois- 
tened in chloroform. 

ZINC CEMENTS. 

The zinc cements — or "osteoplastics" as they are sometimes called — 
used in dentistry are the oxychloride, the oxyphosphate, and the oxy- 
sulphate. The oldest of these is the oxychloride, which was first intro- 
duced to the profession about the year 1850, or a little later, by M. Sorrel 



MANIPULATION AND INTRODUCTION OF PLASTIC FILLING-MATERIALS. 337 

as a permanent filling-material, and on account of its hardness, whiteness, 
and apparent insolubility, it gave promise at first of fulfilling the expecta- 
tions of its inventor, but later all hopes in this respect were abandoned, as 
it was found to undergo rapid disintegration whenever the material was 
placed in contact with the margin of the gum or very near to it, and it also 
contracted very considerably in hardening, and therefore resulted in leaky 
fillings. 

Zinc oxychloride is formed by the combination of calcined and j>ulver- 
ized zinc oxide* with a solution of zinc chloride in distilled water : ZnO -f- 
ZnCl 2 + HP = 2ZnClIIO. 

" Zinc oxide is made by heating metallic zinc in a current of air. To 
make a pure white zinc oxide for pharmaceutical purposes, pure precipi- 
tated zinc carbonate should be heated at low red-heat until the water and 
carbonic oxide are wholly expelled. This can be done below 500° F. Too 
high heat will give the product a yellow color and make it feel harsh. A 
small quantity should be used in heating. A good quality of zinc oxide 
should come in the form of a soft, flaky, inipaliDable powder of sp. gr. 5.6. 
It should turn yellow when heated in a test-tube, and become white again 
on cooling. It is insoluble in water, but completely soluble in dilute acids. 
It is not darkened by sulphuretted hydrogen. 

'•Zinc chloride is made by heating zinc in a current of chlorine, or by 
the action of hydrochloric acid on granulated zinc, or zinc carbonate, and 
evaporating the solution to dryness. It occurs in the form of hard, dirty- 
white masses, very deliquescent, and forming a clear solution in water. It 
is one of the most soluble substances known. Zinc chloride has a caustic, 
sharp taste, and is acid in reaction. It is soluble in alcohol and in ether." 
(Mitchell.) 

Zinc oxychloride as prepared for dental use is composed of a powder 
and a liquid. 

The powder is made by thoroughly triturating in a mortar two grains 
of borax and four pennyweights of zinc oxide. These are then placed in 
a small crucible and subjected to a glowing red-heat for from seven to ten 
minutes, forming what is termed a ■•frit," which when cooled is finely 
pulverized in a mortar. Sixteen pennyweights of zinc oxide are then 
placed in a crucible and subjected to a moderate red-heat for three or four 
minutes, and allowed to cool. After which it is gradually added to the 
'•frit," and the whole thoroughly pulverized and mixed. It should then 
be transferred to a glass- stoppered bottle to protect it from the moisture of 
the atmosphere. 

The liquid is made by dissolving half an ounce of zinc chloride in two 
or two and a half drachms of water, and after several shakings allowed to 
settle for a few days, when the clear fluid may be decanted off. If the 
solution does not clear it should be filtered. (Flagg.) 

Mixing. — For mixing zinc oxychloride, or in fact any of the zinc 
cements, a glass slab and a suitable spatula are necessary (Fig. 4G4). 
Upon the mixing-slab are placed one or two drops of the fluid, and near it 
a quantity of the powder. These are then incorporated and worked into a 
thick creamy paste, and it is ready for use. The filling is introduced into 

22 



338 



OPERATIVE DENTISTRY. 



the cavity by small spatulas (Fig. 465), and adapted to the walls by means 
of pellets of bibulous paper, which remove any surplus of liquid, and thus 
hasten the setting. 

Characteristics and Properties. — Zinc oxychloride sets rather slowly 
and is not so hard when set as the oxyphosphate cements. About fifteen min- 
utes are required for it to set sufficiently hard to allow amalgam to be 
packed upon it without displacement, and half an hour to an hour for a 

Fig. 464. 




Fig. 465. 



Bevelled edge (glass) raising-slab and spatula. 

gold filling. Some operators defer the operation of covering it with a 
metallic filling until a future sitting, protecting the cement with a gutta- 
percha filling until that time, in order that the cement may furnish a 
harder foundation for the metallic filling. 

When used in large masses it shrinks notably. It stands low in the 
scale as a conductor of caloric, and like all compounds which contain zinc 
oxide, it is readily decomposed by the action of acids 
and alkalies. 

Zinc oxychloride is not a definite chemical compound, 
and cannot be made by the method of mixing without 
one or the otherof the constituents being found in excess. 
According to C. S. Tomes, there is always free zinc 
chloride to be found in the finished filling, and conse- 
quently the filling is hygroscopic. 

When freshly mixed, if it is brought into contact with 
vital soft tissues it is irritating and escharotic. Conse- 
quently it should never in the creamy state of the mix be 
brought into contact with an exxDosed pulp, or one nearly 
exposed, as inflammation and devitalization in a large 
majority of instances would be the result. If the ma- 
terial is mixed to a doughy consistency, it may sometimes 
be used as a capping for nearly exposed pulps. The danger to the pulp 
lies in the irritating effect of an excess of the zinc chloride. After the 
filling has set, it retains antiseptic properties for some time thereafter, 
as shown by Miller in his experiments upon the antiseptic properties of 
filling-materials. 




MANIPULATION AND INTRODUCTION OF PLASTIC FILLING-MATERIALS. 339 

Zinc oxychloride lias also an obtunding effect upon hypersensitive 
dentin if left in the cavity for a month or more. It is also, by reason of 
its antiseptic properties, an excellent material with which to fill the roots 
of devitalized teeth. It may be used alone for this purpose, or combined 
with other materials like gold-foil, gold wire, lead, or gutta-percha points ; 
while on account ' of its extreme whiteness it may be successfully used as a 
lining of cavities to restore the color of devitalized teeth. 

Zinc Oxyphosphate. — Cements of this class are formed by a combina- 
tion of calcined zinc oxide and orthophosphoric acid, 3ZnO -f- 2H 3 PO i = 
Zn 3 (P0 4 ) 2 + 3H 2 0, nominally, for on account of the impurities in the zinc 
oxide and of the inconstancy of the acid itself, their actual composition 
is one of considerable variability. 

"Phosphoric acid has modifications — metaphosphoric and pyrorjhos- 
phoric acids — which differ from it in the number of the combined equiva- 
lents of water ; and these forms pass into one another somewhat readily. 
Thus a solution of metaphosphoric acid when boiled passes into orthophos- 
phoric acid ; pyrophosphoric acid may be prepared by evaporating a solu- 
tion of orthophosphoric acid at a temperature of about 215° F. j but it, in 
the presence of water, slowly passes back into the orthophosphoric acid 
at ordinary temperatures. Each of these acids is capable of forming a 
number of different salts — monobasic, dibasic, tribasic, or tetrabasic salts 
— with the same metal, and thus a large number of zinc phosj)hates are 
known." (C. S. Tomes.) 

Zinc oxypliosphate as known to the dentist is composed of a powder and 
a liquid. The powder is zinc oxide, the liquid one of the many forms of 
phosphoric acid. 

When glacial phosphoric acid is used, the cement is termed oxymeia- 
phosphate. Cements which are made from the commercial phosphoric acid 
are not so durable as are those which are made from the pure acid. 

Purity in the materials which enter into the composition of the zinc 
oxyphosphates is a sine qua non. 

Some manufacturers are in the habit of preparing the powder from the 
commercial metallic zinc, and as a result it often contains impurities, like 
the arsenic compounds, which, according to some writers, explains in a 
measure the reason why teeth which have been filled with oxyphosphate 
cement, and vital teeth carrying crowns and supporting bridges which 
have been set with this material, have sometimes been devitalized. 

The writer, however, has never seen a case of devitalization of the 
pulp under zinc oxyphosphate which could not be satisfactorily explained 
upon some other hypothesis. 

Ames, in experimenting on the zinc oxyphosphates (Dental Cosmos, 
1890), prepared specimens of zinc oxide containing seven per cent, of 
arsenous oxide (zinc arsenite), and with this compound applied to cavities 
in vital teeth he was unable to produce devitalization of the pulp. 

The zinc oxide and arsenic compound used in these experiments was 
prepared "by heating in a sealed tube certain proportions of zinc oxide 
and arsenous oxide. In confinement a full red heat will effect a thorough 
combination of the maximum amount of arsenic with the zinc, which 



340 OPERATIVE DENTISTRY. 

seems to be about seven per cent. This is sufficient to give an extensive 
mirror with, the Marsh test. This combination is such that 3000° F. can 
afterwards be applied to the compound in an open crucible without affect- 
ing the composition. This is necessarily the same compound which is 
formed in infinitesimal quantities in the manufacture of cement powders." 
He believes that the arsenic found in the zinc cements is in combination 
with the zinc in the form of zinc arsenite, and that this combination is 
wholly devoid of poisonous properties per se ; and that the combination is 
not broken up to the extent of forming potent arsenous acid, except under 
rare and unjustified conditions. 

To obtain zinc oxide and glacial phosphoric acid in a pure state are 
expensive processes ; the temptation, therefore, of the manufacturers to 
send out materials which are less troublesome to make and of inferior 
grade is very great. 

The powder is made by treating zinc oxide with nitric acid, evaporating 
it to dryness, calcining and pulverizing. (Flagg.) The calcining process 
requires several hours, the material being kept at the highest forge heat 
during this time, thus forming a vitreous mass, which on cooling is re- 
moved by breaking away the crucible. After thorough pulverization it is 
sifted through a fine bolting-cloth and placed in tightly stoppered bottles to 
protect it from the atmosphere, for if it is exposed it absorbs carbon diox- 
ide from the air, and a portion of the material is converted into hydrated 
zinc carbonate. The presence of carbon dioxide is noticed by the effer- 
vescence which takes place in such samples when phosphoric acid is added 
to them, the effervescence being due to the liberation of carbonic oxide. 
Coarse powders, according to Ames, produce cements with greater crush- 
ing stress than those made from fine powder. 

Eollins's process for making the powder is, "Dissolve pure zinc in 
chemically pure nitric acid to saturation, then evaporate to dryness, pack 
in a crucible, and heat until no more fumes are given off. AVhen cool 
break up the crucible, and after separating the oxide of zinc, pulverize it 
to a fine powder." 

Flagg terms the zinc oxide made in this manner "nitrate of zinc," and 
claims it makes a far superior cement to those powders which are produced 
by calcining zinc oxide. 

The liquid which is combined with the powder in making zinc oxy phos- 
phate cement (oxymetaphosphate) is glacial phosphoric acid, HP0 3 
(metaphosphoric acid). This form of the acid is derived by subtract- 
ing two molecules of water from orthophosphoric acid, H 5 PO a — 2H 2 = 
HPO3, metaphosphoric acid. 

Eollins's process of making metaphosphoric acid is, "Take a pure 
solution of orthophosphoric acid, which is easily obtainable, of a strength 
of sixty per cent. ; evaporate it in a platinum evaporating dish until white 
fumes are given off. Then heat it to a bright redness to be sure that it is 
all converted ; cool and make into a thick syrup." (Mitchell.) 

The impurities found in the commercial glacial phosphoric acid forbid 
its use in the making of zinc oxyphosphate cement. These impurities con- 
sist of variable quantities of sodium, calcium, and magnesium phosphates. 



MANIPULATION AND INTRODUCTION OF PLASTIC FILLING-MATERIALS. 341 

"These salts are permanently soluble in the phosphoric acid, and therefore 
give no evidence of their presence by the formation of precipitates. They 
are also soluble in water, which fact has a direct bearing upon the dura- 
bility of cements made with the impure acid. 1 ' (Burchard.) 

The various preparations of phosphoric acid are proverbially unstable, 
and none more so than the metaphosphoric acid used in the formation of 
the zinc oxyphosptiate cements. 

Precipitates are often thrown down in a few weeks after manufacture 
or crystallization takes place. The precipitates are in all probability 
metallic phosphates, while crystallization may be due to imperfect conver- 
sion during the process of heating. These acids are all strongly hygro- 
scopic ; the metaphosphoric acid being slowly converted into the common 
phosphoric acid by abstraction of water from the atmosphere. It is there* 
fore important that the liquid be kept tightly corked when not in use to 
prevent change taking place in it, if the best results are to be obtained 
with the cement. 

Properties and Uses. — Zinc oxyphosphate cements possess certain 
properties which make them exceedingly useful in the daily practice of the 
dentist, the most important of which are : First, as a lining for large 
cavities with thin, frail walls it is far superior to zinc oxychloride, by 
reason of its stronger adhesion to the walls of the cavity, thereby in- 
creasing their strength and lessening the danger from fracture, and its 
greater hardness, which makes it a better foundation for metal fillings ; 
second, as a temporary filling in devitalized teeth which have been placed 
upon probation, in vital teeth having large and very sensitive cavities, 
and in the deciduous teeth of children, by reason of its easy introduction, 
ready adaptability, and its evident obtunding effect upon hypersensitive 
dentin ; third, for sealing in arsenical dressings ; and fourth, for cementing 
crowns, bridges, orthodontic appliances, and inlays. 

As a conductor of caloric it possesses a slightly higher ratio than zinc 
oxychloride. On account of the strong affinity of metaphosphoric acid 
for water it often causes pain when first placed in sensitive cavities by 
abstracting the moisture from the dentinal tubuli, while if placed in con- 
tact with an exposed or nearly exposed pulp the pain is often excruciating. 
This may be obviated by lining the cavity with one of the quick-drying 
ethereal varnishes or by interposing a layer of softened gutta-percha. 

Zinc oxyphosphate, however, should never be used for fillings which 
approach the gingival margin or extend beneath it without guarding this 
vulnerable point with gutta-percha. Zinc oxyphosphate is readily dis- 
solved by solutions of lactic acid, and this is almost always present at the 
crevices of the teeth, along the borders of the gingivae and in the inter- 
approximal spaces. Fillings thus guarded, if well made, will last from 
one to five years, and in favorable cases they have been known to do good 
service for a much longer jDeriod, while the operator will be relieved of 
the anxiety incident to the tendency of the material to disintegrate at the 
cervical margins when guarding is neglected. 

Mixing and Introducing the Cement. — As a preliminary to prepar- 
ing the cement for introduction into the prepared cavity the rubber dam 



342 OPERATIVE DENTISTRY. 

should be adjusted, iu order that perfect dryness of the cavity may be 
maintained during the insertion of the cement and the early stage of the 
hardening or setting process. 

In mixing the oxyphosphate cement one or more drops of the liquid, 
according to the size of the cavity to be filled, are placed upon the glass mix- 
ing-slab, and near it a quantity of powder • with a spatula a portion of the 
powder is then drawn into the liquid and mixed by rubbing with the flat 
surface of the spatula, other portions being added a little at a time until a 
mass is formed of the consistency of soft dough, the surface .being sticky 
or tacky, so that when it is applied to the dried surface of the cavity it 
will adhere or stick. 

Cements which are made so hard that they can be rolled in the fingers 
have not given, in the practice of the writer, as good clinical results either 
iu hardness or wearing qualities as those mixed as above described. 

The instruments which are the most applicable for the introduction and 
packing of the oxyphosphate cements are those generally used for intro- 
ducing amalgam fillings, the spatula-shaped instruments being the most 
useful. 

If the mix has been made of a sticky or tacky consistency, the final 
packing of the filling and the shaping of the surface will be more readily 
accomplished by covering the surface of the instrument with oil, vaseline, 
or glycerol, to prevent the material from sticking to it. The writer pre- 
fers the glycerol for the reason that it is just as good as the other sub- 
stances for preventing the material from clinging to the instruments, while 
it has the advantage of not leaving an unpleasant taste in the mouth. 

The rubber dam should not be removed until the filling has set suffi- 
ciently hard to permit of finishing the surface. The finishing may be ac- 
complished with cuttle-fish disks, Arkansas stones, and burnishers. It 
has generally been thought that the process of crystallization was promoted 
by protecting the filling for some considerable time from the moisture of 
the mouth, and the manufacturers of these cements usually recommend 
covering the surface of the filling with some protecting substance, like 
sandarach varnish, or burnishing hot wax or jmraffin over it. The utility 
of such a procedure would seem to be questionable in the light of recent 
investigations upon the cements, conducted by Ames* and "Wedelstaedt. 

Shrinkage and Expansion. — Ames thinks there is no advantage to 
be gained by protecting the cement fillings for an indefinite period from 
the saliva, as he found a distinct and radical difference in the amount of 
shrinkage when the two classes of cements — viz., first, those modified by 
alkaline phosphates ; and second, those modified by non-alkaline phos- 
phates — were permitted to harden in a dry state ; but when the process of 
crystallization was allowed to take place with the mass subjected to water 
there was a marked modification of the amount of shrinkage, which was 
often changed to expansion in the second class of cements. 

"In the oxyphosphates wherein the phosphoric acid has been modified 
by alkaline phosphates only, the basic phosphate which is formed, and which 

* Dental Cosmos, 1899. 



MANIPULATION AND INTRODUCTION OF PLASTIC FILLING-MATERIALS. 343 

accounts for the hardening of the mass, is of a friable nature, and is of 
itself a porous material ; so that in agglomerating the crystals or granules 
of the zinc oxide it exerts no special force which would result in a drawing 
together of the granules and make evident a shrinkage at the periphery. 

"In the oxyphosphates wherein the acid has been modified by wow-alka- 
line phosphates, the basic phosphate formed has a glassy nature, and not 
only agglomerates, but agglutinates the zinc oxide granules. In the 
previous case the basic phosphate itself becomes porous in its crystal- 
lization ; while in the second case it is a glassy material which agglu- 
tinates the granules to such an extent as to cause a drawing of them 
towards a centre if the composition happens to give a tendency to a 
diminution of volume during the crystallization. This diminution of 
volume sometimes depends on a lack of water of crystallization, which 
if present in the composition would give too rapid setting, but which if 
added to the crystallizing or hardening mass will be taken up and give 
the difference between a shrinkage and zero or an expansion. 

"In the first there is a diminution of volume which is not apparent, 
because the material forms a porous mass, and there is shrinkage towards 
an infinite number of centres instead of one, as in the second class. In the 
second class there may be diminution of volume in the dry state, and zero 
or expansion by furnishing extra water of crystallization." 

Wedelstaedt* in his investigations was surprised to find "that some of 
his experimental fillings of oxy phosphate would expand two millimetres 
beyond the cavity in which they were made, and was equally surprised to 
find shrinkage in some cement fillings when made in fresh teeth and tested 
in moisture. The aniline ran completely around the filling, leaving the 
axial wall of the cavity as well marked as though no cement filling had 
been placed in that cavity." 

Penetration of Moisture.— Wedelstaedtf discovered also that the 
oxyphosphate cements were readily penetrated by moisture, as was proved 
by the fact that out of more than thirty different specimens of cements only 
one was not penetrated from circumference to centre when subjected to the 
aniline test. The same was found true of the oxychlorides, for only one 
sample, " Justi's Acme," was not penetrated by moisture. The writer, in 
conducting a similar series of experiments, found but one form of zinc 
oxyphosphate cement that was impervious to aniline dyes. Specimen 
fillings made from the "Ames Metaloid," after being immersed in aniline 
for ten days, showed no penetration either at the margins of the filling or 
within the mass. 

Crushing Stress. — Wedelstaedt J also found that some of the oxyphos- 
phate cements would sustain a surprising amount of stress when thoroughly 
hardened, and that age, up to a certain point, added very greatly to the 
strength of the filling. Six fillings were made in cylinders of the uniform 
size of two and a half by three and a half millimetres, and all made from 
the same cement and from one mix. These were tested in a dynamometer, 
two at the end of twenty-four hours, when it was found that at a pressure 

* Dental Cosmos, 1899. f Ibid. % Ibid. 



344 OPERATIVE DENTISTRY. 

of from eighty to ninety pounds they crushed to pieces. At the end of 
forty-eight hours two others were subjected to the pressure of the dyna- 
mometer, and sustained a stress of two hundred pounds before going to 
pieces. At the end of seventy-two hours, the two remaining cylinders 
were found to successfully carry a weight of from three hundred and fifty 
to four hundred pounds before crushing. Other fillings, tested niuety-six 
hours after they were made, carried over four hundred pounds of stress 
before going to pieces, which is a sustaining strength superior to that of the 
best-made amalgam or gold fillings. The best-made fillings of the former 
material, according to Black, crush at from three hundred and twenty- 
five to three hundred and sixty pounds of stress, while the fillings made 
from the latter material show a shortening of the mass under a stress of 
three hundred and fifty pounds of from two to fifteen per cent. 

Zinc Oxysulphate.— This preparation is in no sense a filling- material, 
but it is a valuable adjunct to the other materials for protecting and 
capping pulps which are nearly exposed. . 

Zinc oxysulphate is composed of a powder consisting of one part of 
calcined zinc sulphate to two or three parts of calcined zinc oxide. The 
liquid consists of a solution of gum arabic to which a small quantity of 
calcium sulphite has been added. The powder and liquid mixed together 
form a mass which sets quickly and attains considerable hardness. (Flagg.) 

It is non-irritating to sensitive dentin and to exposed pulps, a good 
non-conductor of caloric, slightly astringent, and seems to possess a pecu- 
liar conserving action upon the pulp not shared to an equal degree by any 
other material used for this purpose. 

For protecting nearly exposed pulps a thin paste is made of about the 
thickness of cream, which is carefully flowed over the bottom of the cavity 
and allowed to harden, — setting takes from five to fifteen minutes, — when it 
should be covered with a layer of oxyphosphate. 

In capping exposed pulps a tiny disk of writing-paper or other suitable . 
material is dipped in the paste and quickly and carefully laid over the 
exposure and covered with a small quantity of the paste. When set oxy- 
chloride or oxyphosphate cement may be placed over it and the cavity 
lined with the same material, preparatory to the introduction of a metal 
filling or a porcelain inlay. 

The rubber dam should invariably be used, as the exclusion of all 
moisture is absolutely necessary to the success of the operation. 

VARNISHES. 

Varnishes are often used for lining cavities preparatory to the introduc- 
tion of the plastic fillings, especially of the zinc oxychlorides and oxy- 
phosphates, the object being to protect the sensitive dentin and the pulp 
from the irritation sometimes induced by the action of the acids contained 
in the liquids of these compounds, and by the non-conducting quality of 
the varnish to lessen thermal shock. 

These varnishes are made by combining certain gums and resins with 
alcohol, chloroform, and ether, such as gum sandarach in alcohol, virgin 
rubber in chloroform, Canada balsam, copal, or dammar in ether r and 



MANIPULATION AND INTRODUCTION OF PLASTIC FILLING-MATERIALS. 345 

trinitro- cellulose in methyl alcohol. These solutions should be made thin 
enough to flow readily, and be applied to the cavity by a pellet of cotton. 

As soon as the varnish has dried the cement lining may be introduced, 
the enamel margins having first been freed from any portion of varnish. 
The same precaution must be observed in freeing the enamel margins of 
the cement before the permanant filling- material is introduced, as careless- 
ness in this regard is bound, sooner or later, to result in a leaky filling from 
disintegration of the film of varnish or of the cement allowed to remain 
between the filling-material and the enamel margin. 

Some operators are in the habit of lining with varnish all cavities that 
are to be filled with gold or amalgam, claiming for this method that it 
greatly lessens thermal shock by sealing the open ends of the tubuli and 
interposing a non-conducting film between the sensitive dentin and the 
filling, and prevents discoloration when amalgams are employed. 

The same method is pursued by these operators when filling with 
gutta-percha, especially when employing the "high heat" material, as the 
adhesiveness of the varnish in retaining the first pellets in position is 
considered an added advantage of the varnish lining:. 



CHAPTER XXL 

INLAYS. 

Definition. — As applied to dental surgery, an inlay is a piece of 
any substance, like gold, glass, porcelain, etc., which is inserted in a 
cavity prepared to receive it, or attached to a portion of the crown of a 
natural tooth. The distinction between an inlay and a filling being that 
the inlay is inserted into the cavity in a solid piece and retained in its 
position by means of cement, while a filling is introduced in numerous 
small pieces, which either cohere or weld to make a solid mass, or are held 
together by mechanical pressure or the interlacing of particles, the com- 
pleted filling being held in place by the adaptation of the material to the 
walls of the cavity, assisted by the retentive form which has been given 
to it. 

The dream of the truly scientific and artistic dentist has always been 
the discovery of a material with which to restore those portions of the 
natural teeth which have been lost by the disintegrating effect of dental 
caries, or by traumatic injury, that would be indestructible in the secre- 
tions of the oral cavity, protect the tooth against the further ravages of 
caries, restore its original beauty of form, color, and translucency, and at 
the same time place it in a position to perform all of its functions in a 
normal manner. 

The art of the porcelain- worker has already reached such perfection in 
the construction of artificial crowns that the visible portions of such 
restorations are so natural in their appearance as to be beyond detection 
except by a critical examination. 

The success in this direction has stimulated the desire to successfully 
restore by the same means such portions of the tooth crown as have been 
lost by disease or accident. 

In studying the history of primitive dental art, it will be found that 
the idea of restoring lost portions of the teeth by the introduction of 
inlays is as old as the art itself. In the early Greek epoch, teeth were 
filled with metal inlays by driving solid pieces of lead into the cavity ; while 
doubtless at a still earlier date jade or graystone was used for the same 
purpose, as found in the central incisors of the skull of a man of an 
extinct race, discovered at Copau, Honduras, by Professor Owen, a few 
years ago, and which is now to be seen in the Peabody Museum of Har- 
vard University. 

Inlays made of various materials have been employed by the modern 
dentist, but none possess in so high a degree the many requisites for the 
ideal filling as does porcelain. 

Inlays have generally been used in two classes of cavities only, — viz., 
in very large cavities in the bicuspids and molars the walls of which were 
too frail to support gold fillings, and in cavities located upon the labial 
346 



INLAYS. 347 

surfaces of the anterior teeth when it was desirable to use a material that 
would be less conspicuous than gold, and which would harmonize with the 
color of the tooth in which it was inserted. 

Metal Inlays. — Gold has been recommended for making inlays for 
large compound cavities in the bicuspids and molars, and is still used for 
this purpose by some dentists as a saving of time and strength to both 
operator and patient. 

These inlays are made in two ways. One by swaging gold plate over 
a die made from an impression taken in wax, gutta-percha, a modelling 
compound, or by burnishing gold or platinum-foil to the walls and margins 
of the cavity ; and the other by fusing gold into a matrix made in sand 
and plaster mixed with asbestos modelled from a similar impression. The 
finished inlay is then cemented into place with zinc oxyphosphate cement 
or gutta-percha. In order to secure the swaged inlay against dislodge- 
ment a retaining loop should be soldered to its under side, or pins may be 
attached, which in devitalized teeth maybe made to enter the pulp-canals. 
The fused inlay should be roughened upon the surfaces which come in con- 
tact with the cement for the same purpose, or headed pins may be attached. 

Dr. C. L. Alexander describes a method of making gold inlays* which 
has many good features and may frequently be applied in cases when the 
restoration of contour by the means of porcelain inlays might, on account 
of the severe strain to which this material would be subjected, and its 
liability under sudden and excessive stress to be fractured, be of question- 
able utility. 

The method is equally applicable to vital and pulpless teeth. In the 
former, anchorage is secured by short posts set in such positions as not to 
infringe upon the pulp, while in the latter the pulp-canals are freely 
opened and longer posts so set as to penetrate the canals, as shown at A, 
Fig. 466, the tooth being prepared 
as represented at A. FlG - 46(3 - 

Platinum plate, No. 40 gauge, 
is then thoroughly annealed and 
a piece cut from it of proper shape 
to cover the lingual surface of the 
crown and extend over the mesial 
and distal surfaces. This is bent 
into shape, fitted to its place, and 
a hole punched in it over the open- 
ing to the pulp -canal ; the post is 

then passed through the Opening . Showing deta^ils of the process for making cast fill- 

r s i & ing for incisor. (After C. L. Alexander.) A, post with 

and into the pulp-canal, being long plate adapted; B, restored contour in wax ; C, the 

enough to project a little distance ^ntour invested ; D, cast contour detached; E, E, 

° j. j the finished restoration. 

beyond the outer surface of the 

plate. A small piece of soft modelling compound is then moulded over 
the plate and the projecting end of the post, which when hardened holds 
them in their relative positions. The piece is then invested in sand and 

* Dental Cosmos, October, 1896. 




348 



OPERATIVE DENTISTRY 



plaster, and the post soldered to the plate with pure gold. It is then 
returned to the tooth, the platinum plate carefully burnished to the surface 
of the crown, and the edges are trimmed to the desired shape. An im- 
pression and bite are next taken as for making a crown and set up in an 
articulator with sand and plaster. After removing- the modelling com- 
pound the contour of the tooth is restored in hard wax upon the platinum 
base. A piece of No. 60 gold-foil or platinum-foil is then burnished over 
the wax, covering it except at one wall, preferably the lingual surface. 
The whole tooth is then cut from the model and invested, care being taken 
to completely cover it except at the surface of wax not covered with the 

foil. When hardened the wax 



Fig. 467. 



Fig. 468. 



is boiled out, leaving the metal 
lining the matrix, which acts as 
a carrier for the metal which is 
to be fused into it. The matrix 
is then fluxed, filled with pieces 
of twenty - two - carat solder, 
and the investment thoroughly 
heated, when with a fine blow- 
pipe flame directed into the 
matrix the solder is flowed, 
more being added until the 
matrix is full. After it is re- 
moved from the investment the 

casting is finished and cemented into its position ; the final polishing to be 

done after the cement has thoroughly set. 

Fig. 467 shows the method of restoring a mesio-morsal angle in a vital 

tooth. Fig. 468 shows the restoration of the lingual cusp and inorsal sur- 




Restoration of incisor by Restoration of molar 

cast filling. by cast filling. 

(After C. L. Alexander.) 



Fig. 469. 



Fie;. 470. 




Front and back views of an incisor restoration and 
cast filling for molar. (After C. L. Alexander.) 



Foil matrix invested. Cast filling for 
molar. (After C. L. Alexander.) 



face of a devitalized bicuspid. Fig. 469 gives a labial and a lingual view 
of incisor restoration and cast filling for molar as adapted to vital teeth. 
Fig. 470 shows a more extensive restoration of a molar tooth. This method 
may also be adapted to the makiug of abutments for carrying pieces of 
bridge-work, as shown in Figs. 471 and 472. 

Amalgam inlays were quite extensively used a few years ago in Ger- 
many for restoring the contour of the posterior teeth. These were fur- 



349 



nished by the dealers in several different shapes and sizes, and were set in 
position by means of freshly prepared soft amalgam. The only advantage 
of amalgam inlays is the ease with which they are made, but aside from 



Fig. 471. 



Fig. 472. 





i^J^:^y\ 



Method of bridging with inclined abutment. 
(After C. L. Alexander.) 



Bridge with cast filling abutments. 
Alexander.) 



this they have nothing to recommend them, and are in no respect as good 
as amalgam fillings made in the usual way. 

Porcelain Inlays. — Porcelain is the only material which has so far 
been discovered that can be made to imitate natural tooth-structure, and 
this art, in the manufacture of artificial teeth, has been carried to such 
perfection that when properly arranged and mounted they are capable of 
deceiving any one who is not a professional expert in the art. For this 
reason the artistic dentist has always looked forward to the time when por- 
celain could be substituted for gold and amalgam in filling teeth in the 
anterior part of the mouth and in conspicuous locations in the bicuspids 
and molars. 

Various efforts have been made in the past to introduce porcelain as a 
material for filling teeth, but the difficulties which have always, until very 
lately, surrounded the operation have deterred all but a very few practi- 
tioners from attempting the task. 

The earliest method of using porcelain as a filling for decayed teeth was 
to prepare the cavity — usually in the labial surface of an anterior tooth — 
with slightly flaring walls or bevelled margins, and then to grind a piece 
of a porcelain tooth having a color that would match that of the tooth in 
which the inlay was to be inserted until it would fit the cavity, and re- 
taining it in situ with zinc oxychloride cement, or by packing gold around 
the edges. The writer has seen one such inlay, which was inserted by the 
late Dr. W. W. Allport, that had done service for more than thirty years, 
and was still as perfect as upon the day in which it was completed. The 
method of grinding adopted by the earlier operators was to smear the 
margin of the cavity with a water-color, generally red, and then to place 



350 



OPERATIVE DENTISTRY 



the inlay in the cavity, and after removing it grind those places which had 
received the color as is practised in grinding gum sections to fit the rim 
of a gold plate. 

Another and perhaps better method of fitting such inlays is to take 
an impression of the margin of the cavity — after it has been prepared to 
receive the inlay — with a piece of No. 20 tin-foil, by placing it over the 
cavity and with a soft rubber eraser or a rubber bottle-stopper pressing 
the foil firmly until the margin is sharply marked. This impression 
should then be carefully trimmed to the line of the cavity margin, and the 
pattern glued to the upper surface of the piece of porcelain tooth that 
is to become the inlay to serve as a guide in the grinding. The section 
should be cemented with shellac to a piece of wood on its under surface to 
assist in holding it during the process of grinding. With care, patience, 
and unlimited time at the disposal of the operator a perfect fit may be 



Fig. 473. 

© © e© 

Porcelain stoppers. 

but only after 



Fig. 474. 



in f\ 









Inlay rods. 



obtained, but only after repeatedly 
trying the inlay in the cavity. The 
final fitting of the inlay may be ex- 
pedited by cementing with shellac the 
end of a short section of wire or a 
broken excavator handle to its upper . 
surface, as this overcomes the difficulty f§f|| ||j 
in holding the section during the pro- 
cess of grinding, and offers a ready 
means of inserting and removing the section from the cavity. The time 
consumed in this process of fitting inlays is so great that few people are 
willing to sufficiently remunerate the dentist to make it a profitable or 
popular operation. 

As a means of overcoming some of the difficulties attending this great 
time-consuming operation the dental porcelain manufacturers have placed 
upon the market ready-made porcelain inlays of different shapes, sizes, 
and colors, known as porcelain stoppers (Fig. 473). These stoppers can- 
not be used until they are ground to fit the cavity, which may be done after 
the manner just described. 

Another method is that devised by Dr. G. H. Weagant. which consists 
of cutting inlays from artificial teeth or inlay rods (Fig. 474) by the aid 
of especially devised trephines of five different sizes (Fig. 475), made of 
copper and charged with diamond dust. 

These trephines are to be used in conjunction with How's inlay burs 
(Fig. 476), which correspond in size to the trephines. 

After the decay has been removed from the cavity, a bur is selected 
from the How set which will be large enough to include the utmost limits 
of the cavity, and the final preparation of the cavity completed with it. 
A trephine is next selected which corresponds in size with the How bur. 
and a section cut from an artificial tooth, preferably of English make, 



INLAYS. 351 

whose color matches that of the natural tooth. This inlay is then 
cemented in situ with zinc oxyphosphate, and after the cement has set 
any projection of the inlay may be dressed off with fine Arkansas stones, 
or diamond disks or burs. If English artificial teeth are used, or those of 



Fig. 47r 




Fig. 476. 



©no 

H H 




Weagant trephines. 

the Consolidated Dental Manufacturing Company, the inlay will receive a 
fine polish, and, not being of porous material, it will show no tendency to 
discoloration. This method is, however, open to one very serious objec- 
tion, — viz., the necessity of sacrificing a large amount of sound dental 
tissue in order to give a circular outline to the walls of the cavity. For 
this reason, principally, the method has never been employed to any great 
extent. 

A very beautiful and close joint may be made by this method if 
the joint is ground while the inlay is in situ. This may be accom- 
plished by cutting the inlay a size larger than the cavity which is to 
receive it, and slightly tapering the section until the lower end will freely 
enter the margins of the cavity. It may then be cemented to an engine 
mandrel, and ground into place by revolving it in the cavity, using pul- 
verized pumice moistened with water as the grinding medium, just as the 
plumber grinds the joint of a water-cock. 

Glass Inlays. — Herbst, of Bremen, in 1887, introduced a system of 
making inlays by fusing powdered glass in a matrix of platinum-gold foil, 
made by pressing the foil into the prepared cavity with pellets of cotton 
and burnishing it to the margins. 

The powdered glass, which was made from Venetian glass beads, and 
sold under the names of "Bichter's Glasmasse" (glass-body) and Meyer's 
and Herbst' s Venetian Enamel, was furnished by the dealers in several 
shades, so that it was possible with care to match the color of the natural 
teeth fairly well, and when the inlay was cemented in situ it presented an 
appearance which very closely imitated the vitreous surface of the enamel. 

The method of fusing the glass was to hold the matrix, which had been 
filled with the material, in the flame of a Bunsen burner or alcohol lamp. 
In order to render the glass fusible at so low a degree of heat it was neces- 
sary to reduce the melting-point by the introduction of a large amount of 
flux. This rendered the material soft and porous, so that it was unable to 
withstand the action of the oral secretions or the attrition of mastication, 
and soon lost its satisfactory appearance, first becoming opaque, then dis- 



352 



OPERATIVE DENTISTRY. 



colored, and later almost black, while the surfaces which came in contact 
with occluding teeth disintegrated and wore away like zinc phosphate 
cement. 

The invention of the metalic matrix by Dr. William Rollins, of Boston, 
and described by him in a paper read before the Society for the Advance- 
ment of Oral Science, June, 1880, though almost forgotten for nearly two 
decades, has, nevertheless, the enviable distinction of having led the way 
to, and made possible the construction of, artistic and perfect- fitting porce- 
lain inlays. 

Another important step towards the perfection of this process was the 
invention by Dr. C. H. Land, in 1884, of the gas furnace. Before this 
time the dentist who desired to make a porcelain inlay by fusing the mate- 
rial in a metal matrix was hampered in his work by being obliged to 
depend upon the slow-heating and cumbersome coke furnace. 

This invention was followed by the Downie crown furnace, which was 
still smaller than the Land furnace, and later by the electric oven of 
Custer and the electric furnace of Mitchell (Figs. 477 and 478). 

Since the introduction of electricity as a means of heating furnaces for 
the firing of porcelain the size of the apparatus has been greatly reduced, 
and the time consumed in heating the furnace and firing the porcelain has 

Fig. 478. 




Custer electric oven. 




Mitchell electric furnac 



been curtailed to a few minutes, while the danger from changing the color 
of the material by the presence of gases has ceased to cause anxiety, and 
the noise, dirt, and hard labor incident to working the foot-bellows of the 
gas furnace have all been done away with. 

Porcelain. — Until quite recently the porcelain used for making inlays 
was of the high-fusing grade, the Close or Downie porcelain body generally 
being employed. These bodies require a platinum matrix in which to fuse 
them, as the fusing-point is about 2500° F., which is considerably higher 
than the fusing-point of pure gold. 



INLAYS. 353 

The Downie bodies are furnished in twenty-four different shades of 
color, which makes it possible, when skilfully and artistically combined, to 
reproduce any shade of color to be found in the natural teeth. These 
porcelains are admirably adapted for crown- and bridge- work, but they 
have never been extensively used for inlays, for the reason that a platinum 
matrix is required in which to fuse them, and this material is so stiff and 
harsh, even when annealed in a furnace, that it cannot be readily adapted 
to the cavity walls and margins, and therefore does not furnish so reliable 
a means of taking an impression of the cavity as does gold-foil, and fail- 
ures in the fit of the inlay are more liable to occur. For this reason vari- 
ous efforts have been made to produce a low-fusing porcelain that could be 
fired in a gold-foil matrix, and which at the same time would not be po- 
rous, would not change its color in firing, would be susceptible of taking 
a polish after being ground, would not disintegrate or change its color in 
the mouth, and would have sufficient strength to withstand the stress of 
mastication. 

For several years Dr. N. S. Jenkins, an American dentist, of Dresden, 
Germany, experimented with porcelain, and consulted the best chemists 
and expert porcelain- and glass- workers of Europe in an endeavor to per- 
fect a low-fusing porcelain which would fulfil the requirement of the den- 
tal practitioner for inlay work. In March, 1898, he announced to the 
members of the American Dental Society of Europe — before whom he 
had frequently discussed the question of porcelain inlays, and had re- 
ported from time to time the j)rogress of his experiments — that he had 
finally succeeded in his undertaking ; that he could now pronounce his work 
finished, and desired first to announce his discovery to them, and then to 
the profession at large. The announcement attracted universal attention, 
and dentists everywhere, both in Europe and America, began experiment- 
ing with Jenkins's porcelain enamels and his method of making inlays. 

These porcelains are very finely ground, and are furnished to the pro- 
fession in eighteen different color shades, whites, blues, yellows, and 
browns. Dr. Jenkins says of his porcelain enamel, that he took as his 
model the Ash & Son's tooth, and tried as far as possible to imitate the 
fine texture and character of this porcelain tooth body, but so changed its 
composition as to make it fuse at a degree of heat which would allow of 
its being fired in a gold-foil matrix. Great difficulty was experienced in 
obtaining colors which would not change during the process of firing, but 
he finally succeeded, so that there is absolutely no change at any degree 
of heat which will not melt the gold-foil matrix. 

The permanency of the color in the fluids of the mouth he believes 
is scientifically certain ; the material is not acted upon by any chemic 
substance except hydrofluoric acid, and is so hard and tough that it will 
withstand the stress brought upon it in mastication without appreciable 
attrition or chipping, and retain its polish under the use of the tooth-brush 
and powder. 

Ash & Son, of London, have perfected a high -fusing body in six 
shades, with two shades of enamel, one dark, the other light, which 
Dr. J. Leon "Williams very highly recommends in an article on u Ceramic 



354 OPERATIVE DENTISTRY. 

Art in Kestoration of Teeth" {Dental Cosmos, November, 1899). They 
have also prepared a low-fusing body in seven colors, and one enamel, 
which he thinks are in no way inferior to those prepared by Dr. Jenkins. 

The Consolidated Dental Manufacturing Company of ~New York have 
also prepared and placed upon the market high-fusing and low-fusing 
porcelains made after suggestions of Dr. Joseph Head, which seem to be 
in every way equal to the Jenkins and Ash bodies. 

METHODS OE MANIPULATION. 

The first important consideration in making porcelain inlays is a 
judicious selection of the cases in which this method of filling teeth is to be 
employed. It is not, for instance, applicable to cavities in the distal sur- 
faces of the second and third molars, for the reason that in such locations 
a perfect impression would be difficult or well-nigh impossible to obtain, 
and consequently an inlay could not be constructed which would be as 
good as a metal filling inserted in the usual manner. In all other locations 
in the mouth, with skill and patience, satisfactory inlays may be inserted. 

The locations, however, in which they are most applicable are : 

1. In cavities upon the labial and buccal surfaces of the incisors, cus- 
pids, and bicuspids. 

2. In large cavities located uj)on the approximal surfaces of the six 
anterior teeth and the mesial surfaces of the bicuspids. 

3. In large cavities involving the mesio-morsal surfaces of the first 
molars. 

4. In large morsal cavities in any of the molars when the walls are 
thin and the pulp nearly exposed. 

One of the great advantages of porcelain as a material for stopping carious 
teeth is its low conducting power of caloric, which greatly lessens the shock 
incident to the sudden changes of temperature so constantly taking place 
in the mouth, and which sometimes makes a metal filling unendurable. 

Preparation of the Cavity. — In preparing a cavity to receive a 
porcelain inlay, the same degree of care should be exercised in removing 
the decayed and infected dentin that would be expended upon it if it was 
to receive a gold filling. 

The shaping of the cavity is an important feature, and too much care 
cannot be expended upon it. In general terms it may be stated that the 
cavity should be formed with flaring walls — in other words, cup-shaped — 
without undercuts, and the enamel margins slightly bevelled outward, so 
that when the foil is removed and the inlay is inserted it will set into the 
cavity the thickness of the matrix and fit tightly at the margins. 

In preparing the enamel margins all corners and sharp angles must be 
removed, the outline of the cavity following graceful curves. The bevel 
must not be too great, as this would give a thin edge to the inlay and 
might cause it to chip. In restoring a mesio-morsal or disto- morsal angle 
of an incisor, it is best to leave the margin square at a right angle to the 
morsal edge, as by this method there is less danger of the enamel edge 
being fractured. The margins of all morsal cavities should be prepared 
in the same manner. 



INLAYS. 355 

Preliminary separation of the teeth is an essential in inlay work, as 
plenty of space must be secured if a perfect impression is to be obtained 
and the normal contour restored. 

Taking the Impression. — A perfect impression is a sine qua non, 
without which every effort at making a perfect fitting inlay will prove 
futile. 

The materials which are employed for this purpose are platinum- and 
gold-foils, platinum No. 30 being used for high-fusing bodies, and gold 
No. 30, and occasionally No. 40, for low-fusing bodies. 

Several methods have been suggested for taking impressions of cavities 
in teeth which are to be filled with porcelain inlays. The simplest is to 
cut a piece of foil a little larger than the cavity of which an impression is 
desired — if platinum-foil is used, this should be thoroughly annealed in a 
furnace for several minutes and allowed to cool slowly — and place it over 
the cavity, and then with a ball of cotton, bibulous paper, or amadou, 
held in a pair of slender curved foil-carriers, gently press the foil into 
apposition with the walls of the cavity, smoothing out the wrinkles 
towards the margins, Next pack the cavity with small pieces of amadou, 
holding them in position with an instrument held in the left hand, while 
with a ball-burnisher the enamel margins are well defined. The amadou 
is then removed, and the foil matrix jarred out of the cavity by tapping 
the tooth with the foil-carrier, or by carefully teasing it out with a curved 
pointed explorer. Sometimes the matrix will come away with the amadou 
packing, but if it has to be removed by the means just suggested, a small 
receptacle should be held under the tooth to receive it when it falls. A 
small sugar-spoon or a small pill-box will answer the purpose. The 
surplus foil is then trimmed off a little distance from the line of the 
enamel margin, and the matrix returned to the cavity and moulded as 
before. The greatest of care must be exercised not to change the shape of 
the matrix after it finally leaves the cavity. For this reason some opera- 
tors recommend investing the matrix in sand and plaster, or in powdered 
asbestos and plaster. The writer combines the latter materials in equal 
parts, which form a sufficiently firm and stable investment for the pur- 
pose. The investing material should be mixed quite soft, so that when 
the matrix is laid upon its surface it will embed itself up to the described 
margins of the cavity. 

Some operators think the platinum matrix is sufficiently rigid after 
being fitted to the cavity to need no supporting investment, and this is 
doubtless true when heavy foil is used, but not so with light-weight foil, 
and in any case the investment removes the anxiety of its becoming 
changed in form, and also insures a perfect fit if it has not been altered 
before it is invested. As soon as the investment is dry the matrix is 
ready to receive the porcelain body. 

Another method is to fill the matrix with moderately hard wax or gutta- 
percha before removing it from the cavity, and then, turning it bottom side 
up, invest it. After the investment has hardened, the wax or gutta-percha 
is removed by boiling water. 

The same methods are employed for taking an impression with gold- 



356 OPERATIVE DENTISTRY. 

foil, but greater care is necessary in removing the matrix not to alter its 
shape. Gold- foil, however, has the advantage over platinum that it gives 
a sharper impression of the walls and margins of the cavity, and therefore 
insures a more perfect fit. A tear in the foil at the bottom of the cavity 
is of no consequence, as the body will not pass through it, but a tear oc- 
curring at the margin ruins the fit of the inlay. 

Dr. Jenkins recommends investing the gold-foil matrix in simple pow- 
dered asbestos mixed with water to a thick creamy paste. This investment 
will be found to be sufficiently strong for the purpose, and it can be fired 
any number of times without cracking. As soon as the investment has 
been dried— and this should be done slowly — the matrix is ready to receive 
the body. 

Dr. Yan Woert recommends taking an impression with inlay cement, 
such as that manufactured by the Consolidated Dental Manufacturing Com- 
pany. The method is as follows : Mix the cement to a stiff paste that can 
be manipulated with the fingers, press it into the cavity, — which has been 
previously anointed with vaseline, — and allow it to harden, care being 
taken to use a mass sufficient to overhang the cavity margins in all direc- 
tions. When hard, trim sufficiently to allow it to be removed from the 
cavity without fracturing it. It is then embedded in a piece of warm model- 
ling compound with the impression of the cavity uppermost and the edges 
free. Then cool in ice- water, and make a counter-die of the cement im- 
pression in softened modelling compound. When cooled, this will be 
found sufficiently hard to permit of swaging No. 30 gold-foil to the exact 
shape of the cavity in the tooth. The matrix thus fashioned is to be re- 
moved and invested in moistened powdered asbestos as above described. 
Dr. Yan Woert claims for this method a more perfect fit, inasmuch as the 
matrix was made over a die which gives the exact outline measurements 
of the cavity, and does not leave a deficiency equal to the thickness of the 
matrix. 

Packing the Body and Firing. — The selection of the color for the 
inlay must be done with the shade ring which accompanies the porcelain 
powders, and with the tooth in the moist state. Drying a tooth changes 
its color very materially. The writer selects a porcelain tooth that matches 
the color of the tooth to be filled, and uses this as a guide while baking 
the inlay. First ascertain the basal color, and then any tone may be given 
to it by a proper combination of the other colors. 

The body may be mixed either with distilled water or absolute alcohol. 
In mixing the body a consistency of soft dough should be obtained. It is 
then placed in the matrix with a small spatula, and settled into place by 
tapping the pliers that hold the platinum matrix or the tray containing the 
invested gold matrix. In packing the first instalment of the body it 
should not be allowed to come quite up to the margins of the matrix. If 
the matrix is filled at the first firing, the contraction of the material is 
very likely to warp the matrix and spoil the fit of the inlay. This is now 
placed in the furnace and fired until a glaze appears upon the surface, when 
it is removed, cooled, and returned to the cavity, and the- edges again care- 
fully burnished to the margins. 



INLAYS. 357 

The partially filled matrix is again removed and, if of gold, invested as 
before, and the second instalment of body added to that already fired, 
bringing it up to the edges and giving it the desired contour, but care- 
fully removing with a camel' s-hair pencil any portion of body which may 
have projected beyond the line of the enamel margins, when it is again 
fired. It is a safe plan to replace the inlay in the cavity after the second 
firing and study its contour ; if this is not quite right, more material can 
be added and the piece again fired. 

After the inlay has cooled the foil matrix may be peeled off by starting 
it from the edges first and working towards the centre. If it is peeled 
towards the edges, chipping is likely to occur. Any particles of the foil 
which remain may be scraped off with an excavator, and it is important 
that all be removed, or a perfect fit of the inlay will not be secured. 

In building large contours or restoring the angle of an incisor, a chip 
of a porcelain tooth of the proper color may be placed in the matrix and 
the body built around it. Such cases, however, require to be heated and 
cooled more slowly than small inlays, or otherwise there is danger, from the 
sudden expansion and contraction, of cracking and checking the piece. 

A safe rule to follow is to make all inlays a trifle darker than the tooth 
when inserting them in the labial and buccal surfaces or the approximal 
surfaces of the incisors, as they are less conspicuous if a little darker than 
when a little lighter. In approximal cavities in the bicuspids and molars 
lying well in the shadow of the tooth the inlay should be a trifle lighter 
in shade than the tooth, as the shadow makes them appear darker. 

Williams suggests that the contraction which occurs in firing large 
inlays, which often warps the matrix and thus destroys the accuracy of the 
fit, may be obviated by mixing the porcelain paste to the consistency of 
soft putty, and building a "ring of this putty around the entire circumference 
of the cavity in the matrix, leaving the centre free and empty. In melting a 
porcelain paste it naturally shrinks towards the largest mass of its own 
body, or towards the centre of the mass. If, then, this centre be removed, 
we should naturally expect the mass to shrink towards the circumference, and 
this is precisely what happens when manipulated as directed. The matrix 
always comes out from the first baking with the porcelain everywhere 
firmly melted to the walls of the matrix. Nor will it ever start from this 
position at any subsequent baking unless it is very much overheated." 

Setting the Inlay. — After the foil matrix has been removed, retain- 
ing grooves should be cut at opposite points upon the under side of the 
inlay, in order that firm attachment may be secured to the cement, or the 
inlay may be embedded, face downward, in a piece of warm base-plate wax 
and hydrofluoric acid applied to the back, and allowed to remain for about 
five minutes. On carefully washing the iniay with water it will be found 
that the acid has attacked the surface of the porcelain, removing the gloss, 
roughening the surface, and giving it the appearance of ground glass. To 
this surface the cement will adhere with great tenacity, preventing the 
inlay from being dislodged. 

The edges of the inlay will usually present a slightly thin, jagged ap- 
pearance, as the result of an overflow of the porcelain during the pro- 



358 OPERATIVE DENTISTRY. 

cess of firing ; this should be carefully smoothed off with cuttle-fish disks 
or Arkansas stones. 

The inlay is then secured in place by setting it in zinc oxyphosphate 
cement. Any ordinary cement having a finely ground powder, like the 
Justi or Harvard, will answer the purpose, but these are improved by 
grinding in a mortar until the powder is impalpable. 

Coarse powders do not give good results, as the particles prevent a close 
approximation of the inlay with the walls of the cavity, thus spoiling an 
otherwise good fit. 

An inlay which fits perfectly, and which matches the color of the tooth, 
forms a joint which is almost imperceptible to the unaided vision. 

The cement should be mixed to the consistency of cream and spread 
evenly over the floor and the walls of the cavity. The inlay is then placed 
in position by means of the spatula, which should have a tiny bit of cement 
on its surface to cause the inlay to adhere to it, and then pressed home. 
Pressure should be maintained until the surplus cement has had time to 
escape around the margins of the inlay. 

In approximal cavities, after the inlay has been inserted, a wooden 
wedge may be placed between the approximating teeth to support the inlay 
during the setting of the cement, or cotton and sandarach varnish may be 
used for the same purpose and allowed to remain for twenty-four hours. 
The wedge may then be removed, and any projection of the inlay beyond 
the surface of the tooth dressed off with Arkansas stones or cuttle-fish 
disks. Inlays made from the porcelain furnished by Dr. Jenkins, Ash & 
Son, or the Consolidated Dental Manufacturing Company, will take a 
polish after being ground equal to Ash & Son's artificial teeth. 

A zinc oxyphosphate cement has recently been placed upon the market 
by the Consolidated Dental Manufacturing Company which has been pre- 
pared with especial reference to setting inlays, and is known as "inlay 
cement." Each box contains a bottle of liquid and four bottles of powder, 
representing the four basal colors used in the making of the inlays. It is 
therefore possible with a little care to match the color of the inlay. The 
powders are very fine, and form, when mixed with the liquid, a very 
smooth and fine-grained mass which does not set too rapidly and makes a 
very hard and resistant cement. 

The cement forming the joint of the inlay should be protected from 
moisture for a few hours by coating it with sandarach varnish, melted 
paraffin, or chloro-percha. 

In finishing the inlay the stones and disks should be run in a direction 
from the edge to the centre, and never in the reverse direction, as there is 
danger of chipping the edges of the inlay if they are run in a direction 
from the centre to the edge. The final polishing may be completed with 
pumice and chalk. 



CHAPTEE XXII. 

DENUDATION OR EROSION OF THE TEETH, AND ATTRITION OR ABRASION. 

Definition. — Denudation (Latin, demidare, — de and nudare, nudatum,— 
to lay bare), the condition of a part deprived of its natural coverings, 
whether by wounds, gangrene, or abscess. It is particularly applied to the 
bones when deprived of their periosteum, and to the teeth when they lose 
their enamel or cement substance, or when the gums recede from them 
and their alveoli are destroyed. 

Erosion (Latin, erodere, erosum, — e and rodere, — -to eat away), the 
action of a corrosive substance, or the gradual destruction of a part by a 
substance of that kind. The term is often employed in the same sense as 
ulceration. It is a molecular disintegration of tissue caused by the action 
of some corroding agent. 

Various terms have been applied to this disease, such as denudation, 
erosion, surface wear, abrasion, and atrophy. 

Denudation or erosion of the teeth is a disease which attacks these 
organs, beginning with the enamel and gradually involving the subjacent 
dentin without any of the appearances or characteristics of dental caries. 
It consists of a gradual wasting away of the enamel and dentin, generally 
upon the labial and buccal surfaces, most often beginning with the incisors, 
though it may attack the other teeth first, and may involve all of the teeth 
to the second molars. It usually begins at the gum, forming depressed 
plains, cavities, or grooves, which follow the curves of the gum lines. 
They are as evenly and smoothly cut as though made with a file or disk, 
are highly polished, perfectly hard, and many times absolutely free from 
discoloration. 

The surface of the groove is generally quite sensitive, sometimes ex- 
quisitely so, causing the patient much uneasiness and pain. Occasionally 
the process begins at numerous irregular points on the labial surface, 
which extend, and after a time coalesce, involving the loss of the entire 
enamel wall of this surface. The disease progresses in rare cases as far 
as the pulp, laying that organ bare, while in the majority nature pro- 
vides against it by filling up the pulp-chamber with secondary dentin and 
thus protecting it from exposure. 

In other cases, after progressing to a greater or less extent, it seems to 
become self-arresting. 

The rapidity with which the disease progresses is also variable. In 
some cases the loss of substance will be so slow as to require ten, fifteen, 
or twenty years to reach the pulp-chamber, in others only a little more 
than as many months. The superior teeth are much more liable to be 
attacked than the inferior, though cases are quite common in which both 
are affected, but the writer has never seen the lower teeth destroyed to the 

359 



360 OPERATIVE DENTISTRY. 

same extent as the upper. The bicuspids are most often the seat of the 
disease when located in the lower jaw. 

Causes. — Upon the question of the causation or etiology of the dis- 
ease there is a great variety of opinions. Up to the present time no definite 
conclusion has been reached by investigators as to the real factors of its 
etiology, and our knowledge of the subject is very unsatisfactory indeed. 

John Hunter was the first writer to notice and describe this disease. 
He named the disease "decay by denudation," and thought the disease 
was inherent in the tooth itself, and stated that he had seen cases where it 
appeared as if the outer layer of dentin had been destroyed first, and that 
the enamel afterwards broke through for want of support. 

This theory is evidently erroneous, for no such phenomenon occurs in 
this disease. He has doubtless confounded it with that form of caries in 
which the enamel becomes partially decalcified in spots and permits the 
pathologic condition to extend to the subjacent dentin, when after a time 
they break away together, leaving a shallow cavity more or less irregular 
in form, but lacking that smooth, polished condition which always attends 
a case of true denudation or erosion. 

Bell dissented from the views of Hunter, but expressed himself at a loss 
to explain the cause of the disease. He suggested, however, that the 
cause might be one of faulty development of certain concentric portions 
of enamel, which would render such portions more liable to mechanical 
abrasion or other injury than the rest. 

If such were the true explanation we should expect to see the grooves 
extending completely around the necks of the teeth, but this condition 
never occurs, and yet certain portions of enamel may, as he states, be 
faulty in their development, but not necessarily, however, extending com- 
pletely around the tooth, and thus predispose such teeth to the action of 
solvent agents, as is believed to be the case in dental caries. 

Fox in writing upon the subject frankly admitted that he was unable to 
assign a cause for the disease, but thought that it was dependent upon some 
solvent property of the saliva. If the saliva contains the solvent which 
is responsible for this disease, we would expect to find all the surfaces of 
the teeth equally affected, for they are always more or less in contact with 
it. The inferior teeth are completely bathed in the saliva, so that if this 
suggestion was correct the lower teeth would be most often affected, while 
clinical experience teaches the very opposite to this. 

Wedl describes the disease and classes it among the atrophies, but 
makes no attempt to account for its peculiar manifestations. He calls at- 
tention to the fact, however, that sometimes the mucous membrane of the 
cheeks and lips is raised into a fold opposite the dental arches, and sug- 
gests that it may be well to consider, in future cases, whether any relation 
exists between the defects upon the necks of the teeth and these folds or 
ridges. 

These folds or ridges the writer has noticed many times, but they are by 
no means a constant accompaniment of the disease, and when such instances 
have occurred he has been inclined to consider it a result rather than a 
cause of the disease. 



DENUDATION OR EROSION OF THE TEETH. 361 

Salter calls the affection ''surface wear," and ascribes it to friction of 
the lips, cheeks, and tooth-brush. 

The surfaces of the teeth attacked are those usually reached by the 
tooth-brush, and by many the disease is thought to be one of mechanical 
origin entirely ; but this cannot be the case, for often the grooves or cavi- 
ties will reach around the teeth mesially and distally to points impossible 
to be reached by the tooth-brush or by folds of the mucous membrane of 
the lips or cheeks. 

The break in the tissue is also, in some cases, so decidedly undercut as 
to prove conclusively that such a condition could not have been caused by 
the friction of the tooth-brush. Tomes also observed a case of the disease 
where the patient rarely or never used the tooth-brush, and Mr. Harrison 
reported a similar case at the meeting of the Odontological Society of Great 
Britain in May, 1870. But the most conclusive argument against the me- 
chanical origin of the disease was furnished by Dr. Murie in a paper read 
before the same society at its meeting held in June, 1870, in which he 
related the fact of having found a sea-lion (the Otaria jubata) whose teeth 
showed the results of this disease to a very considerable extent. The posi- 
tions most notably affected were the sides of the teeth where friction 
would be reduced to the minimum ; the tusks or great cuspids were most 
conspicuously affected by the disease. 

Tomes thinks this condition, ' ' at least in so marked a degree, is not 
common among seals, but has seen an approach to it in the teeth of several 
specimens of different species, ' 7 and he further says that in the museum of 
the Royal College of Surgeons may be seen the skeleton of a seal in which 
this condition of the teeth is well exemplified, some of the teeth being 
deeply grooved in positions not exposed to friction. 

Coleman * is inclined to the opinion that mechanical attrition is among 
the possible causes of the affection. In discussing the question of the 
presence of the disease in seals, he points out the fact that some seals are 
known to be in the habit of taking stones in their mouths, and very prob- 
ably sand also ; while hard fish-scales are frequently in their mouths. 
Their long and flexible tongues are also capable of being swept over the 
surfaces of these eroded teeth. It is not difficult, therefore, to suppose 
that by these means the surfaces of the teeth may be worn away. Although 
there is some uncertainty still resting upon the subject, and it is diffi- 
cult to account for, still he thinks from the foregoing that the question of 
mechanical attrition cannot be fairly ruled out as not being among the 
possible causative factors in these animals. 

Bland Sutton thinks there must be some association between erosion of 
the teeth and defective development. In a paper upon comparative dental 
pathology,f after referring to the condition of erosion in seals, he calls 
attention to the reduced dentition of the elephant seal (the Macrorhinus 
coninus) whose peg-shaped molars present a groove around the entire cir- 
cumference, which is perhaps caused by erosion, and also to a skull of the 



* Transactions International Medical Congress, 1881. 

f Transactions Odontological Society of Great Britain, January, lS84-April, 1885. 



362 OPERATIVE DENTISTRY. 

Otaria jubata in the possession of Mr. Bartlett, in which the skull and the 
jaws are affected with a peculiar porous, soft hyperostosis, similar to that 
seen in the skulls of rachitic animals at about the period of puberty. He 
also refers to having found in a raccoon-like dog evident characteristics of 
mollities ossiam, and in which the teeth had undergone erosion. He there- 
fore comes to the conclusion that, from these instances of erosion, associated 
with constitutional bone disease, and with comparatively functionless, im- 
perfectly developed teeth, there must be some connection between erosion 
and defective development. 

He says further, in reference to the process of absorption which some- 
times attacks the functionless tusks of the female Indian elephant, 
1 1 Pathologists have long been aware that morbid changes are more prone 
to attack undeveloped functionless or imperfectly acting organs ; hence I 
imagine that the tusks of female elephants are more prone to inflammation 
than the fully developed representatives in the male." 

Magitot regarded the disease as a result of caries which has been spon- 
taneously cured or arrested by the obliteration (filling up) of the dental 
tubuli. 

It is difficult to understand how this author, for whom the writer has 
the greatest respect, can arrive at such a conclusion from the phenomena 
presented by the disease. If, as he suggests, it is caries in the incipient 
stage, arrested by or cured by the obliteration of the tubuli from a deposi- 
tion of calcareous matter, why is it that in almost every case the teeth thus 
affected are sensitive, sometimes exquisitely so, to the touch of an instru- 
ment, changes of temperature, acid condiments, and confections 1 Calcified 
nerve-tissue has no sensation (assuming that nerve-fibrils penetrate the 
tubuli of the dentin) ; hence his theory in this respect must be erroneous. 
These cases are also usually progressive, many times extending over a 
series of years, and perceptible changes can be noted from time to time. 

Tomes calls attention to another form of the affection in which the loss 
of substance is not merely confined to isolated spots or surfaces, but in which 
the whole exposed portion of the tooth is attacked. "As the morbid 
action goes on the enamel is slowly removed from the crown, so that the 
teeth become shorter and thinner and assume a peculiar yellowish, trans- 
lucent appearance, the position of the pulp being strongly marked by the 
difference in color. In the only case which has come under my own obser- 
vation, the wasting of the teeth was established beyond all doubt by taking 
models from time to time. The patient, an anaemic girl, was reduced to a 
state of great prostration by acute dyspepsia, and was for a considerable 
time confined to her bed ; she was, however, so hysterical that it was ex- 
ceedingly difficult to rightly estimate her condition. At one time there 
was great tenderness of her teeth and general periostitis in the front of the 
mouth, which, judging by color alone, appears to have resulted in the 
death of one of the upper central incisors. The use of alkaline applications 
seemed to have no effect whatever, but the patient's condition has now 
greatly improved, and the disease appears to be no longer progressing. It 
is remarkable that during her prolonged illness, while the teeth were being 
rapidly eroded, no caries occurred in the mouth." 



DENUDATION OR EROSION OF THE TEETH. 363 

The writer has reported a case* of a somewhat similar character occur- 
ring in a gentleman of leisure about forty-five years of age, in which the 
six anterior teeth and the right first bicuspid of the upper jaw are quite 
extensively denuded, the enamel being entirely removed from all of the 
teeth named upon their anterior surfaces, with a considerable portion of the 
dentin, leaving an inclined plane pointing backward, and extending from 
the margin of the gums to the ends of the teeth, shortening the anterior 
teeth to the extent of about a sixteenth of an inch. 

The denuded surfaces were not all grooved in one direction ; the central 
incisors and the left lateral were grooved horizontally like the others, but 
were also grooved longitudinally at the cutting edges. 

The first and second bicuspids of the lower jaw on the right side were 
also affected, but not to the same extent as those of the upper jaw. Fifteen 
years before, Dr. Allport, of Chicago, filled with gold the six anterior teeth 
upon their cutting edges, for the front teeth originally occluded squarely, 
and by mechanical abrasion cup-shaped cavities had been worn into the 
dentin, making it necessary to fill them. The centrals were also slightly 
decayed at the margin of the gums, and small fillings were also inserted 
there. 

Six years afterwards it was first observed that the disease had attacked 
the teeth ; two years later it had progressed so far as to make the edges of 
the fillings stand out above the surrounding tissue on the labial surfaces. 
These edges were rounded off and the case dismissed for the time being. 
Shortly afterwards the gentleman went to Europe and remained there four 
years. On his return not a vestige of the fillings was left, nor even a de- 
pression to indicate where they had been, the surface being as smooth and 
regular as though cut and polished with file or disk. 

There had also been a perceptible loss of structure during the past three 
years, but the destruction had been much less rapid than previously. 

Numerous other cases might be mentioned to substantiate this posi- 
tion, as well as the fact that it does not originate in incipient caries. Cases 
have occurred in their incipiency and progressed stage by stage under our 
eyes, and at no time have they shown any signs of decay. 

In the case just mentioned two of the teeth were slightly decayed at the 
gum line, but none of the others were at any time affected in this way. 

Underwood f reported a case l ' occurring in a lady of middle age, who 
became the subject of erosion after a severe attack of rheumatic gout ac- 
companied by great depression and mental shock of a severe character. She 
had never worn an artificial denture. All of the surfaces of the teeth 
were impartially attacked, so that one bicuspid was reduced to a cube of 
dentin minus the enamel on all sides, while others presented polished 
grooves traversing their surfaces in all directions, contrary to the usual form 
in which the loss of substance is limited to the crevices of the teeth. True 
caries was also present in the mouth ; the reaction of the saliva was 
strongly acid even just after a meal. Two sisters and a niece of the patient 

* Transactions of the American Medical Association, 1884. 
t Aids to Dental Surgery. 



364 OPERATIVE DENTISTRY. 

were free from the affection. One of the sisters, however, had at a later 
period shown signs of the disease." 

The late Dr. Eleazer Parmley, of New York, reported some years ago 
a case in which erosion attacked natural teeth that had been set upon 
an artificial piece in precisely the same manner as in teeth having natural 
attachments to the alveolus. 

J. Tomes and Harris are both inclined to think the disease is one of 
chemical origin. Tomes suggests that it is caused by the fluid secreted by 
the mucous membrane covering the parts affected, undergoing fermenta- 
tion, or affording a nidus for fermentation, and thus may provide an acid 
solvent. 

Harris adopts the opinion that the loss of substance which characterizes 
the affection is produced by the action of acidulated buccal mucus. In 
every other part of the mouth this fluid is mixed with saliva, and the acid 
it contains is so diluted as to prevent it from acting on other portions of 
the teeth. 

The view held by these authors is the one most generally accepted, 
perhaps because no better theory has been advanced. This theory, how- 
ever, does not account for all the peculiarities of the disease. To illus- 
trate : certain teeth are affected in individual cases to the exclusion of 
others. The writer has had several cases where the disease attacked the 
superior incisors and bicuspids, while the canines were entirely free, and 
vice versa, and one marked case of the disease in the lower bicuspids on 
both sides, while all the other teeth of the mouth escaped entirely. 

The writer has frequently tested these cases with litinus-paper to ascer- 
tain the condition of the mucous secretions of the lips and cheeks, but has 
never found any very marked acid reaction ; in fact, has often found greater 
reaction in mouths where the teeth were entirely free from the disease. 

For several years two brothers who were manufacturers of sulphuric 
acid were under the professional care of the writer. One of them had 
charge of the stills, and the other of the chemic laboratory. The former 
was for hours at a time in a room the atmosphere of which would be 
highly charged with the fumes of the sulphuric acid, making it necessary 
to wear a wet sponge over the nose and mouth to protect the air-passages 
from its irritating effects. The latter was also subjected to the fumes of 
the acid, but to a much less extent than his brother. Both of these gentle- 
men suffered very greatly from dental caries during the years that they 
occupied these positions, but when they gave up this part of the work 
there was a marked decrease in the amount and progress of the caries. 

In the brother who spent so much time in the distillery room a con- 
dition similar to erosion occurred upon the labial surfaces of the ten 
anterior teeth of both jaws, but upon leaving this work to be done by 
others the progress of the disease was permanently arrested, as shown by 
the fact that there has been no further progress for the past ten years. 

In an article translated from the German by C. E. Koch, and published 
in the Missouri Dental Journal, August, 1872, the author advances the 
theory that the disease is one having a close analogy to the process of 
resorption, attacking the roots of the deciduous teeth prior to their being 



DENUDATION OR EROSION OF THE TEETH. 



365 



replaced by the permanent organs. He claims that "the gum may secrete 
a fluid endowed with functions similar to those possessed by the absorbent 
organ found at the roots of the deciduous teeth, and by this means the 
tissues are removed, leaving the surfaces, as in the case of the roots of the 
teeth just mentioned, smooth and polished ;" but qualified his statement by 
saying that he " feels inclined to assume at least a predisposition of the tooth 
concerned, for the reason that in all cases only certain teeth are attacked 
by it." He bases his argument, however, upon what he assumes to be a 
fact, — viz., "that denudation always appears upon the neck of the tooth." 
He has evidently overlooked the fact that cases of the disease occur, as we 
have already stated, upon the labial and buccal surfaces, remote from the 
margin of the gums, at points not likely to be reached by the eroding fluid 
in sufficient strength to account for the rapid progress of the disease in 
some of these cases. 



Fig. 479. 



Fig. 4«0. 




V, 




=;,# 



Teeth where the prape-cure has been taken. Case attributed to the use of acid phosphate. 

(After Dr. Darby.) (After Dr. Darby.) 

Fig. 479 represents a case of this character reported by Dr. E. T. 
Darbj r , in which the affection developed while the patient was taking the 
grape-cure, and another case, illustrated in Fig. 480, in which the loss of 
tissue is at the cervices of the teeth, was ascribed to the use of acid phos- 
phate. 

Taft is of the opinion that an acidulated buccal mucus is the essential 
factor in producing erosion, and thinks that constitutional treatment may 
have a controlling effect upon the disease. 

Charles E. Tomes is inclined to the belief that mechanic abrasion does 
not fully account for the disease, and that some other factor must play an 
important part in the process. 

Truman has long maintained that the disease was caused by an acid fer- 
mentation taking place in the mouth, more especially at night or when 
the mouth was in repose, and in corroboration of this theory proved by 
tests with litmus that the secretions of the mouth almost invariably gave 
an acid reaction upon rising in the morning and after a fast of several 
hours' duration. 

Kirk believes erosion to be produced by the solvent action of tire product 
of the buccal mucous glands. 

Garretson was of the opinion that the true explanation of the cause 
of this disease was that enunciated in the experiments of Mr. Kincely 
Bridgman, the author of the electrochemical theory of decay, and he 



366 



OPERATIVE DENTISTRY. 



says, "My present convictions have led me to believe that in this direc- 
tion will be found to lie not only the cause of the disease but the pro- 
phylaxis." He further says, "It would seem, however, that back of the 
immediately acting cause must be a predisposition ; here it would seem to 
be the result of impressions made on the enamel at the period of its forma- 
tion, and which deficiency the nutritive functions have failed to correct. 
It might, indeed, very well be that such enamel is entirely deficient in 
vital resistance, and thus subject to be acted upon as any inorganic struc- 
ture, being by electrolytic action simply dissolved." 

Black* has produced a condition by artificial means out of the mouth 
which closely resembles erosion. In one experiment which he records 
two freshly extracted and sound bicuspid teeth were placed with their 
proximal surfaces together and their roots enveloped in gutta-percha, 
so that their crowns only were exposed. These were then placed in a 
glass jar containing a dilute solution of hydrochloric acid (one to four 
hundred), and by means of a revolving glass paddle-wheel, run by a 
clock-like mechanism and making forty revolutions per minute, a current 
was made to impinge upon their outer surfaces, the current striking one 
with greater force than the other. The result at the end of five days 
was the disappearance of the cusps and the formation of a groove be- 
tween the teeth. This groove was most marked upon the tooth which 
received the greatest force of the current. These experiments were re- 
peated a number of times with slightly varying results. Stronger solu- 
tions produced general soften- 
Fig. 481. ing, while solutions of the 

strength of one of acid to fifteen 
hundred of water, after a three 
months' trial, gave no appre- 
ciable results. Dr. Black, how- 
ever, does not look upon these 
experiments as proving any- 
thing as to the etiology of the 
disease. He says, however, 
"the theory that it is caused by 
acid mucus is supported by 
several who have written on the 
subject, and our present knowl- 
edge affords no alternative but 
the acceptance of the general 
idea that it is the action of an 
acid under some peculiar modi- 
fying influence as yet unknown 
to us." 
Darby maintains that many cases of erosion are associated with the 
gouty diathesis, and believes that this constitutional condition is an im- 
portant factor in the causation of the disease. The accompanying illus- 



Case where there was gouty relation. (After Dr. Darby.) 



Fig. 482. 




After Dr. Darby.) 



American System of Dental Surgery, vol. i. p. 1004. 



DENUDATION OR EROSrON OP THE TEETH. 367 

trations (Figs. 481 and 482) represent cases that were associated with, the 
gouty diathesis. 

The writer has frequently noticed that the teeth most often attacked by 
denudation or erosion are those that are generally classed as medium or soft 
teeth, or are low in vital resistance, the patient often inheriting a peculiar 
cachexia, the scrofulous or syphilitic, which has had a depressing influence 
upon the developmental process, thus lowering the power of vital resist- 
ance and predisposing the teeth, as well as other organs of the body, to 
the ravages of disease. 

There is no doubt that the structure of the teeth is often affected by 
certain diseases. The marks which they leave on particular portions of 
the tissue tell at what time the injury was wrought and indicate the cause 
of the disturbance. Syphilis, sinall-pox, whooping-cough, scarlet fever, 
and the pustular diseases leave characteristic marks by which it can be 
told at what portion of the developmental period their influence was felt. 

A peculiar form of the disease is that in which the loss of the substance 
of the teeth is confined to the morsal edges of the anterior teeth. 

Harris * relates a case of this character in which, during the course of 
two years, a separation was formed between the ends of the incisors of 
three-eighths of an inch. 

Bell has also described a similar case affecting mainly the morsal edges 
of the incisors and cuspids, which could not be brought into contact with 
each other. The opening formed between the ends of the teeth was ellip- 
tical in shape. This form of the disease cannot by any possibility be 
attributed to mechanical abrasion or attrition. By some it has been 
thought to be caused by an acid mucus secreted by the glandular structures 
of the surface of the tip of the tongue, which lying in contact with the 
lingual surfaces of the anterior teeth at the morsal edges — except during 
speech or mastication — would keep the solvent fluid in almost constant 
contact with these surfaces. 

Pathology. — Underwood found in the examination of sections of 
enamel at the seat of erosion that the tissue was structurally defective, 
having an exaggerated granular appearance. Sections of dentin showed 
simply the abrupt ending of the fibrils and tubules as if cut with a sharp 
instrument. An interesting fact was also discovered, — viz., that stained 
as carefully as possible the substance adjacent to the eroded surface does 
not take the stain, a condition that might be expected if really due to the 
action of an acid solvent. 

Black says, "Neither the dentin nor the enamel immediately adjacent 
to the portions being removed, even up to the immediate surface, shows 
any changes whatever, except it be a slight discoloration which is present 
in only a portion of the cases." 

The writer has observed that when discoloration became permanent 
upon an eroded surface caries soon attacked this surface. The disease in 
some cases appears to be self-limiting, while in others it is progressive. 

Treatment. — The treatment of denudation or erosion is very unsatis- 

* Dental Surgery, p. 264. 



368 OPERATIVE DENTISTRY. 

factory, for no remedy lias yet been discovered which will arrest the 
progress of the disease. Certain remedies are sometimes applied in an em- 
pirical sort of way, with the view of checking the progress of the disease, 
like alkaline mouth- washes, antiseptic solutions, and alcohol, and the dis- 
continuance of the use of tooth-powders and stifT tooth-brushes. To relieve 
the extreme hypersensitive condition of the dentinal fibrillce the eroded 
surfaces may be touched with zinc chloride, or if the surface is not exposed 
to view, it may be touched with silver nitrate. 

In the more advanced stages of the disease the cavity thus formed may 
be properly shaped and filled with gold. This operation in many cases 
does not seem to arrest or even check the progress of the disease, for it is 
the exjjerience of most operators- that in from three to six years these 
fillings will be lost by reason of the disease progressing until the sup- 
ports of the filling were dissolved away. 

The writer has found that in a certain few cases zinc oxyphosphate 
cement seemed to exert a controlling effect upon the disease, and in these 
cases the cement fillings lasted exceptionally long. Whether this was due 
to some peculiar action of the cement, to a chance association of a changed 
condition in the oral fluids, or to a natural limitation of the disease, it would 
be very difficult to decide. One marked effect of protecting the eroded 
surfaces with zinc oxyphosphate was the abatement, after a few weeks, of 
the extreme hypersensitiveness. 

ATTRITION OR ABRASION. 

Definition. — Attrition (Latin, alterere, to rub against), any rubbing or 
friction which wears a surface. Applied to the teeth, it is the wearing 
away of the tooth -substance, caused by the friction of mastication . Abrasion 
(Latin, abrasio ; ab, priv., radere, to rub), in dentistry, the wearing away of 
the enamel and dentin upon the morsal surfaces by mechanical means, or 
a loss of substance through friction of a foreign body. 

Mechanical attrition of the teeth is a common condition in individuals 
past middle life and in the deciduous teeth of children. The morsal sur- 
faces of the bicuspids and molars are most often the seat of this loss of 
substance, but when the occlusion of the teeth is such that the six anterior 
teeth impinge squarely upon each other, the morsal edges of the incisors 
and the cusps of the cuspids also become worn away, forming broad surfaces, 
which has given rise to the notion among some of the less intelligent laity 
that some people "have double teeth all around." As the process of attri- 
tion goes on the teeth become shorter and shorter until in some cases they 
are actually worn down to the gums. Some animals, notably the rodents, 
have teeth which grow continually, so that the wear which takes place 
from the severe use to which they are subjected is counterbalanced by their 
continuous growth. Not so with man, for with his teeth when once fully 
developed there is no compensation for wear or injury. Unlike other 
organs and tissues of his body, they are incapable of repairing losses which 
may be sustained by disease, injury, or wear. A certain amount of wear 
always takes place upon the morsal surfaces and edges of the teeth from 



DENUDATION OR EROSION OF THE TEETH. 369 

On the other hand, the wear which takes place in some cases is entirely 
abnormal. 

Causes. — The amount of attrition which may take place in any indi- 
vidual case will depend very largely upon the character of the food, the 
density of the tooth-structure, the form of the occlusion, and the habits. 

It may attack the morsal surfaces of all of the teeth, or it may affect 
only one or two teeth. When the anterior teeth occlude squarely together 
all of the teeth will be worn by attrition. When the occlusion is normal 
only the bicuspids and the molars will be affected, but when the attrition is 
localized it will be due to malposition or irregularity of one or more teeth, 
or to some peculiar habit, like holding a pipe between the teeth always in 
the same location. 

The character of the food plays an important part in the normal wear 
or attrition of the teeth. Foods which are hard and require considerable 
mastication or grinding to reduce them to a proper state to enter the 
stomach cause more surface wear of the teeth than foods which are soft. 
This is particularly noticeable in the museum collection of skulls of abo- 
riginal peoples whose food was coarse and contained much gritty material 
intermixed with it, as a result of their primitive method of grinding their 
cereals. The same conditions are noticeable in the negro of the South, 
and in sailors and soldiers who have been in service for long terms, and 
whose food has been of necessity composed of coarse and hard materials. 

Predisposing Causes. — It has been thought by some authorities that 
the difference in the density of tooth -structure was an important predis- 
posing factor in the attrition of the teeth. Confidence in the importance of 
this theory as a causative factor in the wearing away of the teeth has been 
somewhat severely shaken by the publication of the results of Dr. Black's 
experimental research into the question of the differences of density in 
the teeth of individuals from youth to old age. He found, as already re- 
ferred to in another part of this work, that the differences were so slight as 
to be of no importance as a controlling influence in the predisposition to 
caries, and these conclusions are equally applicable to the predisposition 
of the teeth to be worn away by attrition. 

The most important predisposing cause of mechanical attrition is an 
abnormal occlusion of the teeth. When the teeth of the opposing jaws 
form a normal occlusion, the cusps of the bicuspids and molars interlock- 
ing with each other, the buccal cusps of the superior teeth shutting over 
the buccal cusps of the inferior teeth, and the superior incisors and cuspids 
shutting over those of the lower jaw, the surface wear or attrition will 
occur in the bicuspids and molars upon the sides of the cusps which come 
into antagonism, and thus the grinding and triturating character of these 
teeth will be maintained to the end of life ; while the incisive and tearing 
character of the anterior teeth will be maintained by the same normal 
process or wear. 

If, on the other hand, the occlusion of the teeth is such that the points 
of the cusps of the posterior teeth and the morsal edges of the incisors and 
cuspids only come in contact, a sliding motion of the teeth of one jaw upon 
those of the other becomes necessary in triturating and grinding the food. 



370 OPERATIVE DENTISTRY. 

In time tlie cusps of the teeth are completely worn away, and the moisal 
or incisive edge of the anterior teeth is destroyed, thus reducing the mor- 
sal surfaces to flat planes. As soon as the enamel upon these surfaces is 
lost at any one point, the dentin wears away so much more rapidly than 
the remaining enamel that cup shaped depressions are formed in the 
dentin, which grow deeper and deeper until they become an annoyance 
either from their extreme sensitivenesss or from the retention of food debris. 

The malocclusion of one or more teeth often causes a localized attrition, 
as, for instance, when a lateral incisor or a bicuspid is so rnalposed as to 
throw it out of the normal alignment of the dental arch, thereby causing 
it to interlock with the opposing tooth in such a manner as to produce 
excessive attrition upon the labial or lingual surfaces of these teeth. 

Another cause of abnormal attrition is the loss of several teeth upon 
one or both sides of the jaw, thus throwing extra work upon the remain- 
ing teeth. The most common condition of this character is where the 
posterior teeth have been lost, and the whole labor of triturating and 
grinding the food is thrown upon the anterior teeth. 

Habit is also an important factor in the attrition of the teeth. This 
is noticed in certain individuals who when the mind is engaged are con- 
stantly grinding their teeth together, or who, by carrying the jaw forward 
or laterally, bring two teeth together, and by a constant rubbing motion 
wear away the prominent points of these teeth. The habit once formed 
usually remains, and thus an abnormal attrition of the teeth involved is 
produced. 

Pathology. — Smale and Colyer* claim that attrition is always most 
marked in those individuals who are of a gouty diathesis. 

The only changes observable in the structures of the dental tissues are 
the abrupt ending of the dentinal tubules at the worn surface, the evident 
consolidation of the fibrillar in certain cases, the deposition of secondary 
dentin in the pulp-chamber nearest to the point of surface wear, and 
atrophic changes in the pulp itself. 

Treatment. — In many of these cases treatment is not required. In 
those in which cavities or depressions have been worn in the surfaces of 
the teeth a retentive shape should be given to them and the cavities filled 
with gold. In those in which the pulp has been dangerously approached 
gold crowns may be inserted and the normal separation of the jaws re- 
stored, porcelain facings or porcelain crowns being used in all locations 
in which the artistic sense would be offended by the exhibition of glitter- 
ing gold crowns. 

When the posterior teeth have been lost and the anterior teeth are 
being rapidly worn down, artificial dentures should be inserted and the 
" bite" lengthened so as to relieve the wear upon the anterior teeth. When 
the insertion of artificial dentures will not be permitted, the ends of the 
anterior teeth may be protected by the insertion of gold fillings which 
cover the edges of the enamel and lengthen the "bite," as described in a 
preceding part of this work. 

* Diseases and Injuries of the Teeth, p. 2S2. 



DENUDATION OR EROSION OF THE TEETH. 371 

Abrasion. — By the use of the term abrasion the writer means that loss 
of tooth-substance which is caused by the friction of foreign bodies, as, for 
instance, artificial dentures made upon a metal base or retained in the 
mouth by metal clasps which surround certain teeth ; the undue applica- 
tion of the tooth-brush and of dentifrices ; the use of the clay pipe, and 
of chewing tobacco and the betel-nut. 

The most common cause of abrasion is the friction of metal plates and 
clasps. This condition is most likely to occur when the plate or the clasp 
does not properly fit, thus permitting constant motion during speech and 
mastication. These losses of substance are always at those points upon the 
teeth where the friction has been applied. Such abraided surfaces often 
become exquisitely sensitive and call for treatment. When these abrasions 
occur in locations not readily kept clean caries is liable to supervene. 

Abrasions from the use of the tooth-brush and dentifrices are exceedingly 
rare. A few such cases will, however, present in the practice of nearly 
every dentist, but they apj)ear so seldom that they are usually encountered 
as a surprise. Individuals who have this form of abrasion are those who 
are so scrupulously neat about the care of their mouths that for fear they 
will not keep their teeth clean they employ the stiffest brushes that can 
be found, and often add pulverized pumice-stone to their dentifrices to be 
sure that all stains and deposits are prevented from accumulating upon 
them. These abrasions are usu- 
ally found upon the labial and FlG - 483 - 
buccal surfaces of the teeth, and 
might be readily mistaken for 
denudation or erosion (Fig. 483). 

Abrasions from the use of the 
clay pipe are most frequently 
seen among the people of the 
lower walks of life, particularly 

-, , , . , , Case showing abrasion bv tooth-brush. (After 

among laborers having out-door 6 Dr g B p almer>) 

occupations, who smoke a great 

deal, and hold the pipe gripped between the teeth while at work. The 
stem of the pipe is usually held in the same place, and after a time the 
teeth become worn at this point to such an extent that they do not occlude, 
and an open space the form of the pipe-stem remains when the other teeth 
are in contact. The writer once saw an elderly Irishwoman who was a 
constant user of the clay pipe, in whom the groove formed between the 
opposing teeth at the angle of the mouth was so deep and large that she 
had been of late years obliged to wind the stem of her pipe with a strip 
of linen to make it large enough to be gripped by the worn teeth. 

Abrasion from chewing tobacco is quite common among old sailors and 
the negroes in the tobacco-raising districts of the South, while among the 
native low-caste Hindoos and Burmese, who mix lime with their betel-nut 
to form a pungent " quid," abrasion is very common. Tobacco and betel- 
nut chewers, as a rule, always chew the quid upon the same side of the 
mouth, and as a consequence the abrasion always occurs upon that side. 
The constant friction of the tobacco — which always contains more or less 




372 OPERATIVE DENTISTRY. 

grit, particularly so when the unprepared leaf is used, as by the negroes 
of the South — and of the betel-nut mixed with lime rapidly wears away 
the morsal surfaces of the teeth employed in masticating the quid. 

The writer has seen several cases in which the teeth had been worn to 
such an extent by this process that they did not meet by a fourth of an 
inch. 

The treatment of an abrasion is the same as that employed in erosion 
and attrition. 






OHAPTEE XXIII. 

DISEASES AND INJURIES OF THE DENTAL PULP AND THEIR TREATMENT. 

In a preceding chapter the various stages of caries were described, and 
in the following chapters the treatment of the superficial, progressive, and 
deep-seated stages have been discussed. It now remains to take up the last 
or complicated stage of the disease ; that stage in which the carious process 
has penetrated so deeply into the dentin that it may have nearly or quite 
exposed the pulp and produced irritation and pain in this organ, and 
possibly jeopardized its vitality. 

The pathology of the dental pulp has been most completely studied by 
Wedl, Salter, and Black, and nearly all of the knowledge now possessed 
upon this most interesting and important topic has come to us as a result 
of their researches. The subject, however, still remains a fruitful field for 
further investigation, for many problems are still unsolved and many 
questions need further elucidation. * 

The pathologic changes in the pulp which have been most carefully 
studied and described are those iu connection with hyperaeinia, inflamma- 
tion, secondary deposits, calcareous and fatty degenerations. 

HYPEREMIA OF THE DENTAL PULP. 

Definition. — Hyperemia (Greek, brdp, over ; al;ia, blood), a condition 
of plethora or congestion. Hypersemia of the dental pulp is a condition 
in which the vessels of the pulp are dilated and excessively filled with 
blood. 

Hypersemia may be considered as the most important pathologic condi- 
tion to which the pulp is subject, for the reason that it is a common affec- 
tion and often terminates in the destruction of the organ. Hyperemia 
may be transient or persistent, its character depending upon the nature, 
degree, and duration of the irritation which induces it. 

Irritation is the state of a tissue or an organ in which there is an excess 
in vital movement, commonly manifested by increase of the circulation 
and of the sensitivity. Irritation in some form always precedes hyperaeinia 
and inflammation ; or, in other words, these conditions are always caused 
by some form of irritation. When the irritation is confined to a particular 
portion of the body it is termed local irritation. When it affects the whole 
system it is termed general or constitutional irritation. Hyperaeinia is there- 
fore an expression of a state of irritation which may be either local or 
general. 

Hyperaeinia, however, may be a physiologic or a pathologic condition. 
Flushing of the cheeks as a result of mental excitement produced by joy, 
shame, or anger is an illustration of a physiologic hypersemia ; while the 
redness following a local irritation would more nearly express a pathologic 
hyperaeinia. 



374 OPERATIVE DENTISTRY, 

Transient hyperemia may be induced as an accidental condition in sound 
teeth by thermal shock, by diminution of atmospheric pressure, such as is 
experienced in high altitudes, or by injuries which are not of a serious na- 
ture but sufficient to produce a congested condition of the pericemental 
membrane and, by association therewith, transient hyperemia of the 
pulp. 

This condition rarely produces more than a mild and fleeting sensation 
of pain, but yet is a sufficient reminder of what might ensue if the irrita- 
tion were long continued, and to warn the individual not to unnecessarily 
expose himself to its influence. 

Persistent liypercemia of the pulp is of two forms, — active or arterial and 
passive or venous. 

Active hpyercemia is a condition in which the arteries and capillaries 
of the pulp are excessively filled with blood, and, as a result, abnormally 
dilated. 

Passive hypercemia, or venous hyperemia of the pulp, is a condition in 
which the veins and venules suffer engorgement by reason of compression 
at the apical extremity of the pulp-canal. This condition is induced by 
irritation and a consequent increased flow of blood through the arteries, 
followed by their dilatation and the immigration of the leucocytes. Thus 
the arteries occupy more than their normal space in the canal, while the 
leucocytes fill the meshes of the connective tissue and thus produce com- 
pression upon the veins or vessels of exit. 

The susceptibility of the pulp to external irritation varies greatly in 
different individuals, while age, temperament, and diathesis play an im- 
portant part. Susceptibility to irritation is much greater in youth than 
in adult life, and in persons of high-strung nervous temperament than in 
the phlegmatic. Persons of a tuberculous or syphilitic diathesis are very 
susceptible to all forms of irritation and prone to degenerative tissue 
changes. 

Irritation, on the other hand, is well known to be a prolific cause of 
new formations, provided the irritation is not too intense in character. 
Slight irritations, if of a continuous character, often result in hyperplasias 
of tissue, as, for instance, in the increased development of cement-tissue at 
the apices of the roots of teeth which have been subjected to the irritation 
of malocclusion, the strain of carrying a plate which has been clasped to 
them, or of supporting a bridge ; while if the irritation is excessive it is 
liable to produce resorption or other destructive pathologic changes. This 
is often seen in the roots of devitalized teeth Avhich are in a septic condi- 
tion or are the seat of chronic abscess. 

Again, it is a well-known fact that owing to slight irritations of the dental 
pulp from such causes as produce a slow and gradual loss of the hard struc- 
tures of the teeth, like the abrasions of mastication or of metal clasps or the 
erosion of the enamel at the cervical margins or upon the labial surfaces 
of the anterior teeth, or from slowly progressing caries, secondary deposits 
are formed in the pulp-chamber opposite the point of irritation, and pro- 
ceed synchronously with the destruction of the external tissues until 
the entire coronal portion of the pulp-chamber is filled and the crowns 



DISEASES AND INJURIES OF THE DENTAL PULP. 375 

of the teeth are worn down to the gum. If, however, the process of de- 
struction is rapid the pulp is soon exposed, and hypersemia and inflamma- 
tion supervene, thus putting an end to all chances of protecting the pulp 
by new formations, as such growths are never formed when acute inflam- 
matory symptoms are present. 

Causes. — Hypersemia of the pulp maybe induced by many and varied 
forms of irritation, both local and constitutional. 

Local Causes of Irritation. — These may be divided into external, or those 
which operate from without, and internal, or those which operate from 
within, the pulp. 

External Local Causes. — Caries in its various stages ; traumatic injuries ; 
abrasions ; erosions ; chemic reactions from sweets, acids, etc. ; excessive 
thermic changes ; instrumentation ; mechanic irritation from metallic fill- 
ings ; incompatibility of fillings ; pressure from fillings and other foreign 
substances upon the thinned walls of the pulp-chamber ; galvanic shock ; 
septic infection. 

Internal Local Causes. — Dentinal tumors ; pulp-nodules. 

Constitutional Causes. — Nervous irritability ; plethora; pregnancy. 

Hyperemia from External Causes. — Caries in the deep-seated stage is the 
most common of all the causes of irritation which produce or excite a 
determination of blood to the pulp, resulting in hypersemia. Acute 
hypersemia may occur from caries in any of its stages, but most frequently 
when the disease has progressed so far as to nearly expose the pulp, or it 
has been nearly uncovered by a traumatic injury or by abrasion or erosion. 
External irritants, like thermal shock and chemic reactions, are usually the 
exciting causes of hyperemia. There are, nevertheless, certain individuals 
in whom general nervous irritability and local hyperesthesia may be so greatly 
exalted at times that trivial forms of irritation become unbearable. Under 
such circumstances hypersemia of the pulp may be induced by the most 
superficial cavities of decay, particularly when they are located at the 
cervix of the tooth. In such persons the introduction of metal fillings, 
even in the most shallow cavities, are frequently productive of a persistent 
active hypersemia and severe odontalgia, necessitating the removal of the 
filling before relief can be obtained, while if the filling is permitted to 
remain inflammation of the pulp supervenes. Irritability of this character 
results sooner or later, according to the intensity of the hypersemia pro- 
duced, in either death of the pulp, the formation of secondary deposits in 
the form of dentinal tumors, or pulp nodules, or in a general fatty or 
calcareous degeneration. 

On the other hand, secondary formations or deposits are not infre- 
quently found within the pulp-tissue, which can in no wise be accounted 
for as resulting from external agencies, and which are sometimes productive 
of a most persistent form of irritation, accompanied by severe neuralgic 
pains, while at other times the irritation may assume a low chronic form, 
resulting in various obscure reflex symptoms. 

Chemic reactions from sweets, acids, salt, etc., taken into the mouth as 
food or condiments, when coming in contact with the exposed dentin of vital 
teeth, may, even in the case of superficial caries, in the recession of the gums 



376 OPERATIVE DENTISTRY. 

which exposes the cervices of the teeth, in chemic erosion and mechanic 
abrasions, produce a persistent hypersemia of the pulp, the nature of which 
is determined by the severity and duration of the irritation, the excita- 
bility of the dentinal fibrillar, and the general nervous irritability of the 
individual. 

Excessive thermic changes and chemic reaction, operating upon the ex- 
posed or carious dentin of vital teeth, are the most frequent exciting causes 
of hyperemia of the pulp. The thermic or heat sense of individual teeth 
is often augmented by the action of caries, or by other processes or injuries 
which denude the dentin of its natural protecting covering, so that tem- 
peratures which had been readily tolerated when the tooth was in a normal 
state become under these abnormal conditions painful or absolutely in- 
tolerable ; while, upon the other hand, in neurasthenic individuals, certain 
sound teeth, and sometimes, though rarely, all of the teeth, become hyper- 
sensitive, so that the pressure of mastication is no longer borne with com- 
fort, and contact with foreign substances occurring at the cervices of the 
teeth or at points unprotected by the enamel is exceedingly painful, but in 
which the degree of pressure exerted or the form of contact does not seem 
to hold any relation to the amount or the character of the pain induced. 
The same is true of thermic changes ; the differences in the degree of heat 
and cold beyond the point of toleration do not seem to make any especial 
difference in the intensity of the pain. In the former condition hypersemia 
may be induced as a consequence of irritation, and the pulp, if examined 
at the time, will be found to be passing into a state of disorganization ; 
while in the latter, if the offending tooth is extracted, macroscopic and 
microscopic examination may fail to discover any structural changes what- 
ever in the pulp or the calcified tissues of the tooth. 

Instrumentation, such as is employed in the excavation of a hypersensi- 
tive cavity of decay, is often very painful, and the irritation induced by 
the process will, in certain individuals of exalted nervous irritability, pro-, 
duce an active hypersemia of the pulp. A common form of irritative 
instrumentation, and one which more often results in producing active 
hypersemia, is that caused by the friction of rapidly revolving engine burs 
and disks, which are permitted to heat the tooth beyond the limit of nor- 
mal toleration. The friction induced by the rapidly revolving bur may be 
prevented by causing a stream of tepid water to flow over it from a syringe, 
while the friction and consequent heating of the tooth in finishing a filling 
with sand-paper and cuttle-fish disks may be greatly lessened by lubricating 
the surface with toilet soap or vaseline. 

Incompatibility of metal fillings with the structures of the teeth is often 
productive of serious annoyance from the irritation produced by the pres- 
ence of the foreign body in the hard structures of the tooth, for such it 
must be considered under these circumstances. 

Hypersemia of the pulp which is induced by the presence of metallic 
fillings in the tooth is due, as already intimated, to a peculiar and exalted 
general nervous susceptibility of the individual to various forms of irrita- 
tion, and to an excessive excitability or irritability of the dentinal fibrillse, 
which makes them intolerant of all foreign substances used as filling- 



DISEASES AND INJURIES OF THE DENTAL PULP. 377 

materials, which are very far removed from the dentin in their power to 
carry caloric impressions and electric currents. This is proved by the fact 
that such teeth which have been filled with metals are soon made entirely 
comfortable by the. removal of the metallic fillings and substituting gutta- 
percha or porcelain inlays. 

Pressure of fillings is sometimes a cause of irritation of the pulp, and 
is rapidly followed by acute or active hyperaimia. Pressure sufficient to 
cause irritation can only occur in those cases in which the layer of dentin 
covering the pulp is very thin, or so considerably decalcified as to cause 
it to bend under the stress of the force used in packing the filling into the 
cavity. 

Hyperemia which is caused by this form of irritation rapidly pro- 
gresses to congestion and partial stasis, accompanied by excruciating throb- 
bing pain, and later ending in strangulation of the apical vessels and death 
of the pulp, unless the filling is immediately removed and the irritation 
allayed by local applications to the pulp of soothing or anodyne drugs, 
like the tincture of opium, morphine, or cocaine. 

If, however, continuous pain has been present for more than two or 
three days, conservative treatment of the pulp will usually prove unavail- 
ing for the reason that the irritation has been so violent as to completely 
overcome the resistive powers of the pulp and render recuperation nearly, 
if not quite, impossible. Devitalization then becomes the only means of 
giving comfort to the patient and preserving the tooth. 

Galvanic shoch is another and not infrequent cause of irritation and 
hyperemia of the pulp. This form of irritation is produced in the mouth 
by the contact of dissimilar metals, the surfaces of which are bathed with 
saliva having a slightly acid reaction, as, for instance, the contact of gold 
and amalgam fillings in occluding teeth, or in the approximating surfaces 
of teeth which are not in close contact, but which by the occasional suspen- 
sion of food debris or the oral secretions make and break the circuit during 
the acts of mastication, speech, deglutition, or in other movements of the 
jaws, tongue, and the muscles of mastication. Metal plates occasionally pro- 
duce the same effects when in contact with fillings of a different potential. 
Fillings composed of metals of a different potential placed in the same 
cavity do not— even when moisture can penetrate between them — produce 
galvanic shock, for the reason that the galvanic current established be- 
tween them is continuous, and without the presence of moisture it would 
be very slight indeed, except upon the exposed surfaces, and this soon 
ceases from the gradual oxidation of the surface of the baser metal. When 
gold and amalgam are placed in the rnorsal surface of the same tooth, but 
in cavities separated by a more or less thin wall of dental tissue, painful 
galvanic shock sometimes occurs during the act of mastication, by the 
current being completed and broken by the contact of masses of food 
which are so placed at the time as to form a connection or circuit between 
the two fillings. 

Another source of galvanic shock is the contact of a table fork, knife, or 
spoon with a gold or a bright amalgam filling ; such shock is sometimes 
very painful. 



378 OPERATIVE DENTISTRY. 

The character of the hyperemia produced by galvanic shock will 
depend in large measure upon the intensity < and the frequency with 
which the shocks occur and the susceptibility of the individual to such 
form of irritation. In the one case it may result in acute hyperemia 
and severe attacks of odontalgia, while in another it may develop a pas- 
sive or chronic hyperemia with calcareous deposits or other degenerative 
changes. 

The treatment of this form of irritation should be, invariably, the removal 
of one of the offending fillings and replacing it with a metal like the other, 
or with a material possessing no conducting or electric properties, like 
gutta-percha or zinc phosphate. 

Septic infection is often a source of acute hyperemia of the pulp. This 
is commonly caused by the invasion of the pulp-chamber by the disin- 
tegrating processes of caries. It, however not infrequently occurs in 
those cases in which the pulp has not been exposed, but is still covered 
with a layer of decalcified and softened dentin (pseudo-exposure), the 
tubuli of which are filled with saprophytic and pyogenic organisms which 
readily penetrate to the pulp and establish septic irritation, inflammation, 
suppuration, and devitalization. A thin layer of sound dentin is a posi- 
tive external protection against the infection of the pulp with the pyogenic 
organisms. 

It is nevertheless possible for suppurative conditions to be established 
in the pulp without direct external infection. The presence of pyogenic 
organisms in the blood-current which may have gained an entrance through 
some abrasion of the skin or mucous membrane, or through a wound, or 
pre-existing abscess, has long been recognized. These are capable when 
they become arrested in a vessel of rapidly propagating and overcoming 
the vis naturae of the surrounding tissues and establishing suppurative con- 
ditions. This explains the presence of abscesses of the pulp which are 
occasionally found in perfectly sound teeth, the contents of the pulp- 
chamber having the appearance of the pus found in cold abscesses, and 
which, like the cold abscesses found in the bones and soft tissues of tuber- 
cular individuals, have not and do not present any acute symptoms until 
they are opened, when, if the utmost aseptic precautions are not observed, 
they sometimes take on most violent inflammatory conditions which may, 
in extreme cases, terminate in the loss of the tooth and in establishing 
acute septicaemia. 

Symptoms. — The symptoms of active or acute hypereemia of the 
pulp are sharp, lancinating pains, produced by hot or cold substances 
coming into contact with a vital tooth which has been partially de- 
stroyed by caries, traumatic injury, abrasion, or erosion, or which con- 
tains a metal filling, or by the contact of sweet or acid substances with 
the denuded surface. So long as the shock of irritation of these agencies 
produces a quick, sharp, and transient paroxysm of pain, which reap- 
pears only upon an application of the irritation, it may be safely in- 
ferred that no serious vascular disturbance is present ; but when the 
paroxysms of pain are not only sharp and lancinating, but prolonged for 
several minutes or even hours after contact with these irritating agencies, 



DISEASES AND INJURIES OP THE DENTAL PULP. 379 

it may be suspected that serious disturbances are taking place in the ves- 
sels of the pulp. 

Slight tenderness to percussion or to forcible occlusion is often a sub- 
jective symptom. This is due, in all probability, to an associated sympa- 
thetic hyperemia of the pericemental vessels surrounding the apex of the 
root. The pain, in the absence of active irritation, is usually diffused over 
the entire side of the jaw and but vaguely located, and may be referred by 
the patient to an adjoining tooth or to one in the immediate neighborhood. 
Sometimes the pain is reflected to a tooth upon the same side of the jaw 
but remote from the seat of trouble, or it maybe reflected to the corre- 
sponding tooth or some other in the opposite jaw. Occasionally this symp- 
tom will assume a neuralgic character, the pain being located in the ear, 
or it may manifest itself in the ophthalmic division of the fifth nerve and 
produce lachrymation, hypersemia, or inflammation of the conjunctiva, and, 
even amaurosis. When the pain is neuralgic in character the "points 
douloureux" of Valliex are often well marked in the trifacial nerve. In 
the ophthalmic division these tender points are located at the supraorbital 
foramen, the upper eyelid at the line of union of the nasal bone with the 
cartilage, at the inner angle of the orbit, and in the globe of the eye. 
Another point is near the parietal eminence. 

In the superior maxillary division the tender points are situated at the 
infraorbital foramen, at the point over the most prominent part of the 
malar bone, an uncertain point upon the gum of the superior maxilla, a 
similar point upon the ur>per lip, and another upon the palate. 

In the inferior maxillary division the tender points are found over the 
auriculo-temporal branch just in front of the ear ; another is located over 
the inferior dental foramen, and still another over the mental foramen. 

Diagnosis. — Diagnosis in even the most obscure cases of hyperemia 
of the pulp can usually be made by forcing a jet of cold air into the cavity 
from a chip blower, or by the application of a jet of cold water having a 
temperature not lower than 60° F., thrown from a syringe upon the suspected 
tooth. In the absence of a cavity, fillings should be sought for and tested 
by the same means. Failing with these, hot water may be used in the 
same manner. Or the positive pole of the galvanic current may be ap- 
plied. As a rule, the application of any one of these methods will render 
the diagnosis sure by immediately stimulating a responsive twinge of pain. 
More rigorous means will excite a severe paroxysm of pain in the offending 
tooth and aggravate the neuralgic symptoms. 

Pathology. — The principal and characteristic pathologic change which 
takes place in active hyperemia of the pulp is an irregular dilatation of its 
blood-vessels. Salter * (1S75) was the first to discover this peculiarity of the 
vessels of the pulp while studying the pathology of suppurating and 
sloughing pulps. He describes the condition as an irregular dilatation of 
the smaller vessels into ampullae filled with clots, and which he believed to 
be due to engorgement of the vessels, loss of vital contractility, passive 
yielding of the over-distended and thinned walls, and coagulation of the 

* Dental Pathology and Surgery. 



;so 



OPERATIVE DENTISTRY. 



blood. Albrecht*(lS5S) called attention to the notable increase in the 
volume of the blood vessels and to their tortuous course. Wedl f (1870) 

Fig. 4S4. 
I 




Eypersemiaof the dental pulp, showing the natural injection of the vessels, (After Black.) a, a, 
membrana eboris, or layer of odontoblasts; 6, 6, b, b, vessels distended with blood ; c, c. c, c, points from 
which the blood has fallen in handling the section. 

also describes a swollen and lax condition of the fibrous sheaths of the 
small arteries and veins. 

Fig. 485. 




Dilated blood-vessels from the dental pulp in hypersemia, from tooth extracted during a paroxysm of 
intense pain. (After Black.) 

Black X (1886) found the dilated and varicosed condition of the vessels 
of the pulp (Fig. 4S4) to be so constant as to form a characteristic patho- 



* Krankheiter der Zahnpulpe. 
% American System of Dentistry. 



f Pathology of the Teeth. 



DISEASES AND INJURIES OF THE DENTAL PULP. 381 

logic feature of the acute form of the affection. Fig. 485 was made by Dr. 
Black from a section of the pulp of a tooth which was extracted during a 
paroxysm of acute pain. The tooth had been troubling for several weeks, 
the paroxysms of pain being excited by very trivial changes in tempera- 
ture and lasting for an hour or more. He also found in other cases of a 
similar character, but which were extracted during an interval between 
the paroxysms of pain, that nothing of a remarkable character was pre- 
sented. The veins of a bulbous portion of the pulp may be abnormally 
large and engorged with blood, while the arteries will be almost or quite 
empty and the injection of the capillary system wanting. Black looks 
upon the increased susceptibility of the pulp to thermal shock as a in a 
large degree due to nervous phenomena. The tension of the blood-vessels 
and their degree of contractibility are phenomena which are controlled by 
the vasomotor system, and in the dental pulp these are prominently 
affected by thermal changes in such a way that the vessels expand passively 
before the pressure of the circulation." 

The dilatation of the vessels is due to a paralysis of the vaso-constrictor 
fibres, and the varicosed condition to an irregular paralysis of these fibres. 
The effect of painful stimulation or irritation upon the vasomotor system 
of nerves is to cause an immediate contraction of the vasoconstrictor 
fibres of the walls of the vessels and narrowing of their lumen ; this is 
followed by reaction and stimulation of the vasodilator fibres, which 
cause a dilatation of the lumen of the vessel, and permit a greater quan- 
tity of blood to flow through it than is normal, which constitutes a transi- 
tory hyperemia. In persistent hyperemia of a pronounced type the 
vasoconstrictor fibres suffer paralysis for a time, resulting in a continued 
expansion of the vessels, which may become permanent if the irritation is 
of a continuous character. 

Black found as a result of his researches that the vessels of the pulp 
possessed a wonderful degree of recuperative power, and that the vessel 
walls frequently, recover their normal tonicity. 

In the more advanced stage of arterial hyperemia another phenomenon 
is sometimes presented. This is the escape or migration of the red blood- 
corpuscles through the walls of the vessels, forming areas of a reddish 
hue, and in other instances of deeper color, having the appearance of ex- 
travasations of blood. These are in all probability due to embolism and 
the formation of an infarct. An infarct is a dark-red, wedge-shaped area 
in an organ due to the occlusion of a vessel by an embolus, with the sub- 
sequent extravasation of blood into the tissues beyond the point of obstruc- 
tion. The base of the wedge is towards the periphery of the organ, and 
the apex towards the point from which the blood-clot entered the obstructed 
vessel. 

Passive or venous hypercemia can only be inferred from the character of 
its symptoms, which are dull, heavy, gnawing pains, accompanied by a 
sense of fulness, the intensity of the pain often being steadily maintained 
for many hours. These symptoms are probably due to the dilatation of 
the arteries which enter at the apical foramen, causing pressure upon the 
veins and preventing the escape of the blood from the pulp by these chan- 



382 OPERATIVE DENTISTRY. 

nels. Iii teeth possessing two or more roots, the hypersemia may be some- 
what lessened by the escape of the blood through the veins of a second 
root. In single-rooted teeth this cannot occur, and if the congestion ex- 
tends to the apex of the tooth, the pain will continue until strangulation or 
general infarction takes place. 

Prognosis. — Hyperseniia from external irritants, if unrelieved, usually 
leads to diffuse inflammation of the pulp, probably as a result of infarc- 
tion and the extravasation of the red blood-corpuscles. Cohnheim's ex- 
periments seem conclusive that inflammation does not result from even the 
most extreme hyperseniia that can be induced by the paralysis of the vaso- 
motor nerves. Black * was not able to determine whether diffuse inflam- 
mation would occur before infarction and extravasation had taken place 
or not, but was inclined to believe with Cohnheim that it would not. His 
own observations, however, show conclusively that in every case of ex- 
travasation a mild form of inflammatory action had been induced, by 
which new elements were thrown out which acted the part of absorbents 
in the removal of the extra vasated blood, and in this way he believes a 
general diffuse inflammation of the pulp may be set up as a result of 
hyperseniia. He thinks this will explain those cases of diffuse inflamma- 
tion of the pulp which often occur without the exposure of the organ to 
any of the forms of external irritation. 

Absorption of the extra vasated red blood-corpuscles takes place through 
the phagocytic action of the leucocytes. 

The progress of active hyperseniia will depend upon the temperament 
and the general health of the patient, the duration and character of the 
irritation, the severity and frequency of the paroxysms of pain, and the 
extent to which the crown of the tooth has been destroyed by caries or 
other causes. 

The power of the pulp to recover after repeated attacks of hyperseniia 
points strongly to a favorable prognosis in those cases which have escaped 
infarction and septic infection ; provided the temperament, age, and the 
general health of the individual do not operate against it. 

Conservative treatment should therefore be adopted in all cases in 
which a favorable prognosis may be hoped for. It is not to be expected, 
however, that every case so treated will prove successful, any more than 
that one should expect every case in which the pulp is removed to prove 
successful. A certain number will prove failures in either case, but the 
percentage of successes and failures will depend (after the individual 
equation of the patient has been eliminated from the proposition) very 
largely upon the diagnostic ability and manipulative skill of the operator, 
coupled with good judgment in the selection of the particular method of 
treatment to be employed. 

The writer maintains that inasmuch as the pulp of the fully calcified 
tooth is its organ of nutrition and sensation, it has two important functions 
to fulfil, — functions which should be preserved as long as possible, that the 
tooth may perform to completion its many offices as nature intended ; and 

* American System of Dentistry. 



DISEASES AND INJURIES OF THE DENTAL PULP. 383 

furthermore, that the pulp should never be ruthlessly destroyed, because, 
forsooth, it has sounded an alarm on the too near approach to its citadel 
of the arch-enemy, dental caries. 

Many operators look upon all efforts to conserve the vitality of the 
pulp, after it has given evidence of being the seat of hyperemia, as largely 
experimental, with the chances of failure very greatly in the ascendency, 
and for this reason advise devitalization and extirpation as the surest way 
of rendering the tooth comfortable. 

Other equally skilful and conscientious operators attempt the con- 
servation of the puliD even after it has been the seat of hyperaernia for 
several days, and succeed in a good per cent, of cases in preserving their 
vitality, as proved by their responding to the usual tests many years after- 
wards. 

The age and the general health of the patient are important factors in the 
recuperative powers of the pulp. Conservative treatment of the pulp is 
much more likely to prove successful in youth and early adult life than in 
middle life or old age, while in the debilitated or those suffering from 
tuberculosis or other infectious diseases the prognosis is very unfavorable. 

Treatment. — The rational treatment of any surgical disease or injury 
comprehends two general principles : first, the removal of the cause ; and 
second, rest of the organ or part which should ap proach complete physiologic 
rest as nearly as possible. These principles should always be carried out in 
the treatment of dental diseases, for they can be as readily applied in this 
class of diseases as they can in the more serious surgical diseases or 
injuries. 

In the treatment of hyperaernia of the pulp, the first effort should be 
directed towards giving relief from the pain, and this can best be accom- 
plished by the removal of the cause of irritation. When the disturbance 
to the pulp arises through a carious cavity in the tooth, this should be 
freed from food debris by carefully syringing the cavity with tepid water 
to which has been added in proper strength a suitable alkali or an anti- 
septic. Bicarbonate of soda is the best alkali for the purpose, and listerine, 
pasteurine, borolyptol, thymolene, and formol are the best of the prepared 
antiseptics. The simple removal of the debris and neutralizing the acid 
condition of the disorganized dentin will often be all that will be required 
to give immediate relief from the pain. The next step is to remove the dis- 
organized dentin, care being taken not to expose the pulp, as an accident 
of this character complicates the treatment and renders the prognosis of the 
case somewhat more doubtful. 

The writer believes with many other practitioners of somewhat ex- 
tended experience that it is better practice to leave a layer of decalcified 
dentin over a living but hyperaemic pulp than to remove this covering and 
substitute for it a foreign substance, which can by no possible stretch of 
the imagination be thought to be as compatible to the pulp as the tissue — 
though partially disorganized — which nature formed for its protection ; and 
for the further reason that such practice gives better results, in conserving 
the organ, than does capping with a foreign substance. 

The cavity should now be dressed with some remedy possessing sedative 



384 OPERATIVE DENTISTRY. 

and antiseptic qualities, like the oils of cloves, cinnamon, thyme, gaul- 
theria, peppermint, etc., applied upon a pledget of cotton and sealed in 
with temporary stopping or zinc oxyphosphate. Carbolic acid is recom- 
mended by some operators, while others object to its use because of its 
coagulating effect upon the albuminoids of animal tissue. The object in 
sealing the dressing into the cavity with these substances is to secure rest 
to the |3ulp by preventing or lessening thermal shock, and also to prevent 
its further contamination with septic material, as by this method only can 
one expect to succeed in permanently allaying the irritation of the pulp 
and reducing its hyperseniic condition. Plugs formed of cotton saturated 
with gum sandarach cannot fulfil these requirements, for they soon become 
saturated with the secretions of the mouth and filled with myriads of or- 
ganisms, and should, therefore, never be employed in any case where 
the maintenance of aseptic conditions are desirable. 

The dressings should be allowed to remain undisturbed for two or three 
days or longer if the tooth continues comfortable, otherwise they may 
be changed every day. Care should be exercised in applying the dressing, 
and in each after-treatment, to prevent the entrance of moisture from the 
mouth. To insure this condition it is better to resort to the rubber dam 
than to rely upon napkins or other means for excluding moisture. If after 
a week's treatment the tooth remains in a comfortable condition, the pulp 
may be protected from thermal shock by varnishing the cavity and placing 
a layer of softened gutta-percha in the bottom of the cavity, and filling the 
balance with zinc oxyphosphate, or thin zinc oxyphosphate may be flowed 
over the bottom of the cavity and the balance filled with gutta-percha. 

The treatment of exposed pulps is given in a following chapter upon 
this subject. 

In those cases in which the hypersemia is associated with abrasions, 
erosions, or superficial cavities the surfaces may be treated with carbolic 
acid (deliquesced crystals) or caustic potassa when located in the anterior 
part of the mouth, or with silver nitrate when located in unexposed posi- 
tions. Or a retentive form may be given to the denuded surface, the cavity 
thus made being first treated with carbolic acid and then dried, varnished, 
and filled with zinc oxyphosphate. 

When the irritation and hypersemia are due to the presence of large 
metallic fillings or to galvanic shock from contact of fillings of dissimilar 
metals, these should invariably be removed and replaced with non-con- 
ducting materials. 

Hyperaemia from Internal Local Causes. — Hypersemia of the pulp 
may be induced by certain internal causes, — viz., the formation of secondary 
growths within the pulp-chamber or within the parenchyma of the pulp 
itself. 

These growths are designated as dentinal tumors and pulp-nodules. 

Calcifications of the pulp resulting from the irritation of caries and 
other destructive loss of the hard tissues, and calcareous degeneration, are 
rarely, if ever, causes of hypersemia of the pulp, but are quite often the 
results of hypersemia. 

These formations have, however, been frequently found in teeth which 



DISEASES AND INJURIES OF THE DENTAL PULP. 385 

had given no history of irritation or pain ; it has, therefore, been ques- 
tioned whether they are ever sources of hyperemia. Some have thought 
them to be the result of irritation and hyperemia, while others have be- 
lieved they may sometimes not only be the cause of this disturbance, but 
the more serious condition of facial neuralgia. 

This form of hypersemia is sometimes termed idiopathic, for the reason 
that there seemed to be no other disease upon which it was dependent for 
its origin or progress. In a certain number of these cases there is not the 
slightest evidence of any external form of irritation whatever. In fact, 
the teeth are perfectly sound, the most careful examination failing to reveal 
the minutest trace of a break in the continuity of the enamel, either from 
caries, abrasion, erosion, or other injury. We must, therefore, in these 
cases, look for internal causes of irritation which are to be found in the 
presence of dentinal tumors and pulp-nodules. There are, however, no 
symptoms which are particularly or peculiarly diagnostic of these forms 
of irritation. The diagnosis must therefore be reached by a process of 
exclusion. 

The prognosis is decidedly unfavorable in this class of cases so far as the 
vitality of the pulp is concerned, for sooner or later the pulp succumbs to 
the irritation and devitalization takes place. 

Treatment. — The treatment of hypersemia due to irritation produced 
by the presence of secondary deposits within the rjulp-chamber to be cura- 
tive must be radical. This consists of devitalizing and extirpating the 
pulp and filling the canals with suitable materials. 

Hyperaemia from Constitutional Causes. — General nervous irri- 
tability or neurasthenia is a term which has come into general use to indicate 
certain states of the nervous system — often inherited — the anatomic basis 
of which is still unknown, but which are characterized upon the one hand, 
as pointed out by Putnam, by a series of negative symptoms manifested by 
a lack of vigor, efficiency, and endurance, affecting usually a large num- 
ber of nervous functions, and, upon the other hand, by signs of active 
derangement, which in part seem to occur as positive symptoms, and in 
part are due to a failure of the mutual support and control which the dif- 
ferent parts of the nervous system afford each other in health. These con- 
ditions are often manifest in the mentally and physically overworked, in 
low conditions of the general health, particularly in anaemic states of the 
blood, and in those suffering from prolonged wasting diseases, like tuber- 
culosis and cancer, or from digestive or intestinal derangements and from 
nervous shock. 

Neurasthenic patients are also subject to various sensory disorders like 
neuralgic attacks and periodic headaches, irritability of the spinal cord, 
which upon pressure produces painful peripheral sensations in the region 
of the thorax or abdomen, according to the level at which the pressure is 
made. Another quite common variety of painful sensation, not precisely 
neuralgic in character, is a distressing sense of pressure and tenderness at 
the vertex or occiput, with stiffness of the muscles of the neck. Occasion- 
ally the pain is very severe, and entirely unfits the individual for the time 
for any form of physical or mental labor. 

25 



386 OPERATIVE DENTISTRY. 

Dr. Allbutt, in speaking of this class of individuals, says, ' ' They are 
heirs of every true neurosis, from insanity to toothache." 

Rypercesthetic conditions of the peripheral terminations of the nerves, 
especially of the skin, are frequently met with in neurasthenic individuals. 
These conditions are characterized by an exalted or exaggerated sensibility 
of the skin, which is unattended by any observable structural changes 
whatever. In mild cases there is manifested an undue sensitiveness to 
contact with foreign bodies, such as the clothing, while in the severer 
cases the greatest distress is occasioned by even the passage of a feather 
over the surface. This disease is properly classed with the neuroses of the 
skin, and may be either idiopathic or symptomatic in its origin, but little 
is known of its etiology or pathology. 

Conditions similar to this are sometimes manifested in teeth which give 
no other evidence of disease ; teeth in which the integrity of the enamel 
has not been broken ; but it is an open question whether the sensation of 
pain is primarily due to an exalted sensibility or hyperesthesia of the den- 
tinal fibrillar, and located in them alone or in the pulp, the susceptibility 
of which has been abnormally increased to all forms of external irritation. 

Although the exact anatomic and histologic character of the dentinal 
fibrillse have never been positively demonstrated, yet there is no good 
reason for doubting that they are terminal nerve-fibres, for they seem in 
many respects to possess in a high degree the functions of nerve-tissue. 
It is, therefore, not a severe strain upon the imagination to suppose the 
dentinal fibrillse capable of assuming an excessive sensibility or hyperses- 
thetic condition as an expression of the neurasthenic state of the patient, 
or that such expression may be primarily manifested in the pulp itself, 
which becomes abnormally sensitive to external impressions that under 
other conditions would cause no pain or uneasiness whatever. 

In those cases in which loss of substance has occurred in the crown of 
the tooth from caries or traumatism sufficient to expose the dentin, it 
would seem that the hyperesthesia begins in the dentinal fibrillse and ex- 
tends through them to the pulp. This view receives support from the fact 
that if these cases are treated with silver nitrate applied to the exposed 
dentin, the hyperesthesia rapidly disappears and the tooth regains its 
normal sensitivity. 

General plethoric conditions of the system and pregnancy are often pro- 
ductive of hypersemic states of the dental pulp, by reason of the increased 
arterial pressure which accompanies these conditions. Some of the most 
obscure cases of odontalgia that the writer has ever had to deal with have 
been finally traced to one or the other of these conditions. 

Plethora may be defined as a condition in which the volume of the blood 
in the body is in excess of the normal amount (polywmia), and in which 
the vessels of the body generally, or of any part, are over-distended with 
blood. It is made manifest in flushing of the face, a sense of fulness in 
the head, buzzing in the ears, and full pulse, caused by the increased 
arterial tension and fulness or engorgement, particularly of the capillary 
system of blood-vessels. 

Plethora is more common in men than in women, and is most frequently 



DISEASES AND INJURIES OF THE DENTAL PULP. 387 

seen in middle life. It has been stated by Jacobi that plethoric conditions 
are present in women just before the menstrual periods. 

Osier is of the opinion that the conditions which are denominated 
plethora are the result not of an actual increase in the volume of the 
blood, but rather to its distribution and certain local peculiarities of the 
vessels or of their innervation. 

Individuals of this dyscrasia are prone to capillary hyperemia ; to 
rupture of the arterioles and capillary vessels and extravasations of the 
blood, by reason of the continued increased blood-pressure, and the con- 
sequent weakening of the walls of the vessels. This is illustrated by the 
fact that this affection furnishes a fair proportion of the otherwise healthy 
individuals who suffer from a general distention of the superficial vessels, 
hyperemia, and hemorrhagic conditions of the mucous membrane of the 
upper air-passages, as well as that more serious and often fatal affection 
known as cerebral apoplexy. 

The tendency in plethoric individuals to general distention of the super- 
ficial blood-vessels and engorgement of the capillaries the writer believes 
sometimes results in hyperaemia of the pulp in perfectly sound teeth, 
accompanied by pulsating sensations, a sense of fulness or throbbing pain 
which may be referred to one or more teeth. In other cases it may result 
in rupture of the vessels, extravasation of blood, inflammation, and death 
of the pulp. 

The diagnosis of hyperemia of the pulp caused by plethora is quite 
readily made from the general condition of the patient, the absence of any 
discoverable external cause of irritation, and the previous history of the 
case, which is invariably a sense of fulness, accompanied with occasional 
pulsating or throbbing sensations in the tooth, which are augmented by 
vigorous exercise or the recumbent position ; later the pulsating or throb- 
bing sensations become painful, which indicates the establishment of the 
hy perse in ic state. 

Treatment consists in reducing general and local arterial tension. This 
may be accomplished in the first instance through a general depletion of 
the system by the administration of saline cathartics, a restricted diet, and 
regular exercise. Local arterial tension may be relieved by the hot foot- 
bath, keeping the extremities warm, the bowels open, and the skin free. 
If general treatment fails to give the desired relief and the pain continues, 
the only recourse is the devitalization and extirpation of the pulp. 

Pregnancy. — Pregnancy, although a physiologic process, is often pro- 
ductive of various disordered states of the system. It will be sufficient in 
this connection, however, to dwell simply upon those abnormal conditions 
of the oral cavity which are referable in a greater or less extent to the 
usual augmentation in the volume of the blood during this period, and to 
a plethoric state of the upper half of the body, which is not an infrequent 
accompaniment, and to those nervous phenomena which are productive at 
this period, of neuralgic conditions of the trifacial nerve. 

Changes both quantitative and qualitative occur in the blood during 
pregnancy. The quantitative change in the blood is proved by the in- 
creased area of the circulation brought about by the enlargement of the 



388 OPERATIVE DENTISTRY. 

uterus and by the fulness of the vessels, a fulness which is sometimes pro- 
ductive of varicose veins or of serous effusion. This increase in the 
volume of the blood was first demonstrated by Spiegelberg and Gescheidlen * 
in experiments upon pregnant bitches. 

Authorities, however, are not agreed as to the qualitative changes 
which take place in the blood. Andral,f Nasse,| Meyer, § and others claim 
that the watery elements and the white corpuscles are increased and the 
red corpuscles diminished. Ingerslev || was unable to detect any diminu- 
tion in the number of red corpuscles, while, upon the other hand, Fehling % 
found the hseniaglobin and the red corpuscles increased. 

Temporary hypertrophy of the left ventricle sometimes occurs as a 
result of increased labor thrown upon the heart as a consequence of the 
augmentation of the blood mass. This was first made known by Larcher ** 
in 1828. 

Venous congestion, varices, and swelling of the lower extremities, and 
arterial hyperemia of the upper half of the body, are a frequent accom- 
paniment of pregnancy. The causes of these conditions are not fully 
understood, but they were attributed by Christoforis f f to pressure of the 
gravid uterus upon the iliac veins, which prevented the normal return of 
the blood to the inferior- vena cava, and to pressure upon the descending 
aorta, thus obstructing a normal flow of blood to the lower extremities, and 
causing plethora or arterial hyperemia of the upper portion of the body. 

An increase in the salivary secretions is often a noticeable symp torn. 
Ptyalism when present manifests itself early, and usually disappears spon- 
taneously between the third and fourth months. It occasionally persists, 
however, in an exaggerated form during the entire period of gestation, 
and even for several weeks thereafter, while the amount secreted may be 
so great as to endanger the life of the patient. The qualitative changes 
in the saliva during pregnancy are sometimes quite marked. The water 
is increased, while the organic and inorganic elements are diminished. 
Schramm reported one case in which the pytalin was entirely absent. In 
those cases in which an excessive flow of saliva is manifest the buccal 
mucous membrane is more or less inflamed, the parotid, submaxillary, and 
sublingual glands are swollen, tender, and quite painful when their secre- 
tory functions are especially excited. Fcetor is not present, and the 
absence of this symptom distinguishes it from mercurial ptyalism. 

The cause of this disorder is generally thought to be due, in all proba- 
bility, to a reflex neurosis, though the writer is inclined to the opinion that 
it is due to over- stimulation of the glands resulting from the general hyper - 



* Hirst's American System of Obstetrics, p. 353. 

t Armales de Chimie et de Physique, Juillet, 1842. 

t Archives of Gym, Bd. ix. S. 338. 

\ Untersuchungen liber die Veriinderungen des Blutes in der Schwangerschaft. 

|| Centralb. f. Gym, 1879, p. 635. 

If Archives f. Gym, Bd. xxviii. Heft 3, S. 454. 
** Hirst's American System of Obstetrics, p. 346. 
ft Ibid. 



DISEASES AND INJURIES OF THE DENTAL PULP. 389 

emic condition of all the tissues of the upper portion of the body 
during this period. The affection frequently reappears in successive 
pregnancies. 

Gingivitis is another common oral symptom in pregnancy, and is often 
present when there is no indication of salivation. These cases are charac- 
terized by redness and tumefaction of the gums and a tendency to bleed 
on slight pressure or friction, while the secretions of the mucous glands 
are often decidedly acid in reaction. 

Phagedenic pericementitis is occasionally an accompaniment of preg- 
nancy, and is frequently associated with rheumatic affections, diabetes 
mellitus, and albuminuria, but just- how it is associated in relation to 
cause and effect with the kidney affections is not positively known, but 
the writer has suggested* that "it is due in these cases to the accumula- 
tion of effete products in the system, possibly of uric acid, urea, and other 
waste material." 

Neuralgic affections are also quite common during pregnancy, and most 
frequently affect the face and head. Odontalgia is a not infrequent accom- 
paniment of pregnancy in teeth which, so far as external conditions are 
presented, appear to be perfectly sound. This affection is due to hyper- 
emia of the pulp induced by the augmentation in the volume of the blood, 
the increased arterial pressure, and general hyperemia of the upper por- 
tion of the body. 

The proof of this statement is in the fact that a brisk cathartic will 
often relieve or entirely control an attack of odontalgia when due to these 
causes. It operates in a general way by depleting the circulation, thus 
relieving the arterial tension and hyperemia ; while it acts locally by re- 
ducing the blood-pressure in the pulp, and restoring for the time being a 
normal circulation. 

On the other hand, anemic states of the blood are prone to establish 
general and local neuralgic conditions. Anstie has graphically epitomized 
the definition of neuralgia as " the cry of the hungry nerves for food.'' 1 The 
trifacial nerve is frequently the seat of neuralgia, the pain often being 
located in one or more teeth. Cases are on record in which tooth after 
tooth has been extracted under the belief that hyperemia or inflammatory 
conditions were present in the pulp of such teeth, when in reality the 
cause of the affection was a general one, due to an impoverished condition 
of the blood, which in many cases could undoubtedly have been relieved 
by appropriate general tonic treatment. 

Eeflex neuralgic phenomena in the teeth are occasionally encountered as 
a result of diseased conditions of remote organs, or of hyperplastic or hyper- 
trophic enlargement of portions of tissue or organs, or of new growths, 
which cause pressure upon important nerve-trunks, or upon the nerves 
directly supplying the teeth. Consequently in the diagnosis of all obscure 
cases of odontalgia due weight should be given to the possibility of the 
affection having its origin in some one of these remote causes. 

* Paper on " The Teeth of Pregnant Women," Transactions of the American Med- 
ical Association, 1889. 



390 



OPERATIVE DENTISTRY 



Fig. 48G. 



NEW FORMATIONS. 

Calcic Formations within the Pulp-Chamber. — The formation of 
secondary growths of dental tissue within the pulp-chamber and calcic 
degenerations of the tissues of the pulp have never 
been satisfactorily classified. 

Salter was the first to attempt to classify the vari- 
ous forms of new growths within the pulp-chamber, 
and for many years it was the only classification used. 
Black has since made a more minute and comprehen- 
sive classification, but this, he thinks, is still far from 
complete or satisfactory. 

Salter divides secondary growths of dentin into 
three different forms, — viz., dentin of repair, dentin ex- 
crescence, intrinsic calcification, or osteodentin. The accom- 
panying illustration (Fig. 486), borrowed from Salter,* 
represents these forms of secondary growths in the 
pulp-chamber : a represents a mass of dentin of repair 
formed to compensate for the wear at the summit of 
the cusp ; b, an excrescence or tumor projecting from 
the side of the cavity into the pulp ; c, represented 
by the dark cylinder in the axis of the pulp, indicates 
where the formation of osteodentin or intrinsic calci- 
fication begins. 

Dr. Black f classified the secondary deposits within 
the pulp-chamber under six different forms, — viz. : 
11 1. Secondary Dentin. — A new growth of dentin more or less regular 
in formation, excited by abrasion, decay, or other injury, by which the 
dentinal fibrils are subjected to irritation at their distal ends. 

u 2. Dentinal Tumors within the Pulp- Chamber. — An erratic growth of 
dentin into the pulp-chamber united to the wall by a pedicle. The structure 
is very irregular. 

"3. Nodular Calcifications among, but not of, the Tissues of the Pulp. — ■ 
These are the irregular nodulated masses so frequently seen either as very 
small stones or irregular masses. They contain many calcospherites. 

"4. Interstitial Calcifications of the Tissues of the Pulp.— These are the 
counterpart of calcifications elsewhere in the body, as in the arteries, etc. 

"5. Cylindrical Calcifications of the Pulp. — The tissues in this form are 
probably in a state of fibrous degeneration, which is usually seen in the 
pulp -canals. 

"6. Osteodentin. — Erratic formations showing both the lacunae of bone 
and the dentinal tubes." 

Calcospherites were seen by Black in connection with many of these 
forms. Other irregular formations are found that are scarcely assignable, 
he thinks, to any of these varieties, and it is not unusual to find the vari- 
ous forms intermixed with each other. 




Dental Pathology and Surgery. 



f American System of Dentistry. 



Pulp-chamber 




jndarv dentin 



Fig. 487.— Secondary dentin on wall of pulp-chamber. (V. A. Latham.) X 100. 



Secondary 
dentin 









Pulp-chamber 













Fig. 488.— Secondary dentin on wall of pulp-chamber. (V. A. Latham.) v -: 96. 



Pulp-chamber 




Pulp-chamber 




Pulp-chamber 



Secondary dentin 



^-Secondary dentin in base of pulp-chamber. (V. A. Latham.) ;< 50. 



Pulp-nodule 






Dental pulp 



% 






Fig. 491.— Section of dental pulp containing a pulp-nodule. (V. A. Latham.) X 23. 



DISEASES AND INJURIES OF THE DENTAL PULP. 391 

Secondary dentin, or dentin of repair, may be distinguished from the 
other forms of secondary deposit by the fact that it is always located oppo- 
site some lesion of the external tissues of the tooth, whereby a loss of 
continuity has occurred ; that it is adherent to and in direct structural con- 
tinuity with the primary dentin ; that the pulp is not attached to, nor is its 
structure involved in, the newly formed mass, but may be easily removed. 

This process may be regarded as physiologic, having a similar signifi- 
cance to the process of repair exhibited in bone-tissue. 

For further discussion of this subject, see chapter on " Conservative 
Treatment of the Pulp." 

Dentinal Tumors. — These are rare forms of secondary growths within 
the pulp-chamber. They are composed of calcific material of notably irreg- 
ular structure, formed in masses of varying size, and attached by a pedicle 
to the primary dentin, or occasionally to masses of secondary formation. 
They are confined entirely to the pulp-chamber. The dentinal tubes 
within the mass are continuous with the tubules of the primary dentin 
(Fig. 487). 

Dr. Black is of the opinion that they are the result of the same causes 
as those leading to the formation of secondary dentin generally. With 
this opinion the writer cannot fully agree, for the reason that such growths 
have been occasionally found in teeth in which there were no evidences of 
any external cause of irritation. Of the circumstances which determine 
the erratic tumor-like form of the growth nothing whatever is definitely 
known. Figs. 488 and 489 show two very erratic forms. Wedl and Heider 
believe it is due to an inversion of the layer of dentinal cells, and that the 
space formed within the surface of the pulp by the inversion is later 
occupied by new dentin. They say, " These formations are by no means of 
rare occurrence, and that they are found attached to the original dentin 
by means of a pedicle, and in cases where there is no con- 
nection with a pedicle detachment has ensued." 

Nodular Calcifications, or Pulp-Stones. — These are 
found in globular masses (Fig. 490) and spindle-shaped 
masses scattered through the substance of the pulp, par- 
ticularly in the teeth of adults. They may be found in 
any part of the pulp-tissue, but most often in the coronal 
portion. In form they are irregularly nodulated, appear- 
ing to be made up of an aggregation of smaller nodules. 
In structure they appear to be masses of calcific material 
composed of the same elements as dentin, but lacking its 
peculiar structure. Embedded within the calcific material 
are numerous bodies made up of concentric rings, which are calcosphe- 
rites. Various irregular lines are seen running through the mass, which 
may be tubules or only faults in the structure. 

The formation of pulp-nodules is thought to be due to the deposition 
of masses of calcoglobulin within the pulp, and which is known to form 
the base of the pulp-nodule, — the calcospherite, enamel, dentin, and bone, 
— the lime-salts entering into combination with the calcoglobulin to form 
calcospherites, and these uniting in larger masses form the pulp-nodules. 




392 OPERATIVE DENTISTRY. 

Wedl, Salter, Black, and other writers look upon their presence in the 
tissues of the pulp as a result of some form of peripheral irritation of the 
dentinal fibres, as, they are found in increasing numbers in the teeth of 
those who have suffered from caries, abrasion, erosion, inflammatory con- 
ditions of the pericementum, or other injury or disease. Figs. 491 and 492, 
which show a pulp-nodule in situ, are made from a pulp removed from a 
tooth which was the subject of pyorrhoea alveolaris. Tomes does not quite 
agree with this view, as he found globular masses in three out of five speci- 
mens of perfectly sound molar teeth removed post mortem from subjects 
in the hospital morgue. Eobin and Magi tot called attention to the pres- 
ence of isolated calcareous granules of globular form which were scattered 
through the substance of the pulp in the early stages of dentin formation. 
Henle and others have likewise described them as present in the teeth of 
man, ruminants, and rodents. C. S. Tomes found them in the developing 
teeth of ruminants, scattered freely through the dentinal pulp, and finally 
becoming embedded at various depths within the substance of the dentin. 

The fact, therefore, remains that many cases of calcific nodular forma- 
tions within the pulp have their origin in other than external causes of 
irritation. Black looks upon the presence of a few pulp-nodules in the 
tooth as of no special pathologic significance as far as the future health of 
the tooth is concerned. 

Calcification of the Tissues of the Pulp. — This is a condition often 
seen in the teeth of elderly persons, as the result of senile change or de- 
generation of tissue. Fibroid degeneration (Fig. 493) is one of the most 
common precedents of calcareous deposits in the pulp. 

Calcareous deposits formed within the structure of the tissues, according 
to Ziegler, usually occur in localities where the tissues have already lost 
their vitality or are in a process of degeneration or necrobiosis. It appears 
as if dying tissue which has undergone more or less modification possesses 
a kind of attraction for the lime-salts which are in solution within the 
body, and enters into intimate combination with them. The tissues which 
are most prone to calcareous degeneration are connective tissue which has 
undergone hyaline degeneration or sclerosis, the walls of blood-vessels, 
tumors, and other portions of the body which are undergoing hyaline or 
fatty degeneration, degenerating cartilage, dead cell-bodies, and cheesy 
areas of considerable size. 

Tissue- calcification is uniformly associated with degenerative changes 
in the structures of the pulp. Calcification may affect small or large areas, 
causing in the latter case a distinct hardening of the tissue and a whitish 
coloration. 

The process is characterized by the formation of numerous minute 
islands of calcification scattered through the tissue of the pulp, of regular 
outline, and presenting a smooth surface. 

There is considerable difference in the microscopic appearance of these 
islands of calcification. In some of them are seen on section the calcified 
tissue elements of the pulp, others appear to be of granular structure, with 
a few irregular and wavy tubes scattered through them, and still others 
appear to have no structure at all. 



Pulp-nodule 




Fig. 492.— Vertical section of deutal pulp, showing pulp-nodule. (V. A. Latham.) 



k 




Fig. 4l>3. — Section of tooth-pulp undergoing fibroid degeneration. (V. A. P; 



DISEASES AND INJURIES OF THE DENTAL PUEP. 



393 



Salter and Black both describe a peculiar form of degenerative calcifi- 
cation occurring in the radial portion of the pulps of teeth, particularly in 
the roots of the molars, which they have termed cylindrical calcification. 

Fig. 494. 




Cylindrical calcification of the pulp, early stage. (After Dr. Black.) 



From the appearances exhibited in sections of cylindrical calcification, 
it is evident that it is a calcareous degeneration of a previous fibrous 
degeneration of the pulp. This is shown in the accompanying illustrations 
by Dr. Black. Fig. 494 shows an early stage of the degenerative process ; 




Cylindrical calcification of the pulp, early stage ; nodules teased apart. (After Dr. Black.) 

Fig. 495 is a similar section in which the nodules have been spread out to 
show the attachment of the cylindrical masses to the fibrous elements of the 
pulp ; while Fig. 496 shows a more advanced stage of the disease in which 
the cylinders run together and join end to end, forming jointed rods, but 
do not coalesce. In this stage of the disease the radial portion of the pulp 
becomes stiffened and maybe bent at various angles, and will retain its 
bent position. Salter says— and Black agrees with him— that ultimately 
"the whole of the tissues, cells, nuclei, connective tissne, blood-vessels, 
and multitudes of nerves are swallowed up and obliterated in the calcific 



394 



OPERATIVE DENTISTRY 



process. The process of calcification is clearly not interstitial in the sense 
of being between the fibres." This variety of calcification is usually asso- 
ciated with other forms, and there is generally more or less calcification of 
the coronal portion of the pulp, either in the form of secondary dentin or 

Fig. 496. 




Cylindrical calcification of the pulp, advanced stage. (After Dr. Black.) 

interstitial calcification. Figs. 497 and 498 illustrate such a condition, the 
coronal portion of the pulp being completely calcified. 

Osteodentin is a secondary formation of rare occurrence in the human 
teeth, but it is common in the teeth of animals, particularly in ver} 7 large 

Fig. 498. 





animals, like the elephant. These formations are the result of long- con- 
tinued or chronic irritation. As its name implies, it is a form of secondary 
growths which combine the elements of both dentin and bone, or, more 
correctly, of cementum (Fig. 499). It is developed, according to Salter, 
by the general conversion and intrinsic calcification of the several tissues 
of the pulp. It is usually vascular, frequently arranged in systems around 
vessels, like the Haversian systems of bone, and it sometimes has true 
lacunas. It has fewer dentinal tubules than any other form of dentin, and 
is usually very transparent. It is made up of various calcification islands 
or systems of secondary dentin, which are finally fused together and ad- 
herent to the primary dentin (Fig. 500). The mass may contain any 
number of Haversian systems and numerous true bone lacunas, especially 
resembling those found in the cementuni. 

These masses of osteodentin are found in teeth which show marked 



DISEASES AND INJURIES OF THE DENTAL PULP. 



395 



evidences of a former resorption of dentin, and although in many cases 
the tissues increased in amount, a considerable portion was found to occupy 

Fig. 499. 




Section of osteodentin. (After Salter.) 



the situation of the normal dentin which had been removed by the pro- 
cess of resorption. 

Bodecker* has also described this form of new growth as secondary 
dentin with forms analogous to Haversian systems. 

Fig. 500. 




Section of ost< 



I Colyer. ) 



Occasionally the resorbed dentin will be replaced by bone. Fig. 501, 
which is taken from the "Transactions of the Odontological Society of 
Great Britain," 1893, shows a section made from a partially erupted tooth, 

* Dental Cosmos, 1879. 



396 



OPERATIVE DENTISTRY. 



the root of which had apparently been about two-thirds formed, and ap- 
peared as though it had been fractured, but upon microscopic examination 
it was found that this appearance was due to resorption. The bone-tissue 
occupies the cavity formed by the process of resorption. 




Section of dentin showing resorption area occupied by bone-tissue. (After Smale and Colyer. ) 



Irritation and hyperemia of the pulp, it will be seen from the fore- 
going descriptions, could hardly occur from any of the various forms of 
secondary deposits except those mentioned under the head of internal 
local causes, — viz., dentinal tumors and pulp-stones, — by reason of the fact 
that all the other forms of secondary deposits are conversions of tissue, 
while these are erratic growths, occupying space in the pulp-chamber or 
in the tissue of the pulp, where they produce pressure upon the nerve- 
filaments, causing irritation. 



CHAPTER XXIV. 

INFLAMMATION OF THE DENTAL PULP. 

Definition. — Inflammation (Latin, inflammatio, from inflammare, to in- 
flame : inflammo, I set on fire), is a condition of nutritive disturbance, char- 
acterized by hyperseniia, with proliferation of the cells of a tissue or organ, 
and attended by one or more of the symptoms of pain, heat, swelling, dis- 
coloration, and disordered function. Inflammation is a series of changes in 
a part identical with those which are produced in the same part by injury 
from a chemic or a physical irritant. 

Pulpitis is the term applied to inflammation of the dental pulp. (Latin, 
pulpa, pulp, and itis, a suffix used to indicate inflammation.) 

Physical Signs. — The physical signs or cardinal symptoms of inflam- 
mation, as described by Celsus, are four in number, — viz., rubor, tumor, 
calor, and dolor, redness, swelling, heat, and pain ; a fifth symptom has 
since been added to complete the description of the physical phenomena 
as presented in the tissues, — viz. , functio loesa, disturbance of function in 
the part. 

Inflammation is a symptom of disturbed function, but not a disease. 
It is an effort upon the part of the system to eliminate or render inert or 
harmless the primary cause of the disturbance. 

All forms of inflammation are the result of the action of certain forms of 
irritation. Irritants are classed under four general heads, — viz., mechanic, 
chemic, septic, and nervous. 

Mechanic irritants produce irritation through their mechanic action. 
Examples : the presence of foreign bodies, pressure from external sources, 
pressure from new growths, traumatisms, accidental or surgical, etc. 

Chemic irritants are substances which irritate by virtue of their chemic 
reaction upon the tissue elements with which they come in contact. Ex- 
amples : alkalies, acids, and escharotics, like chromic acid, or certain 
coagulants, like carbolic acid and silver nitrate, or violent irritants, like 
croton oil and cantharides. Other examples are found in drugs which 
through their constitutional exhibition produce peculiar effects upon cer- 
tain tissues and organs, and which if administered in toxic doses will cause 
inflammation. Mercury acting upon the tissues of the mouth and salivary 
glands produces stomatitis and salivation. Cantharides will cause irrita- 
tion of the urinary organs, ergot of the uterus, and uric acid will produce 
gouty inflammations. The toxic inflammation caused by the poison of 
serpents and certain insects, the poisonous action of certain plants, like 
the Rhus toxicodendron, and the ptomaines are examples of still other groups 
of chemic irritants. 

Septic irritants are living organisms, — parasites or micro-organisms, — 
which cause irritation by their presence in the tissues or by the elabora- 

397 



398 OPERATIVE DENTISTRY. 

tion of toxic substances — ptomaines — as waste products and their intro- 
duction into the system by absorption. The pus- microbes and the sapro- 
phytic germs belong to this class. 

Nervous irritants are those which produce irritation through the medium 
of the nervous system by disturbing the normal functions of the part. 
The influence which is exerted by the nervous system over the functions 
of nutrition, both generally and locally, in the production of inflammatory 
symptoms has long been recognized. 

Impairment of the nutrition of the skin is sometimes observed to follow 
injury of the nerves supplying the part. Degenerative changes have been 
known to take place in the pulps of the lower teeth following exsection of 
the inferior dental nerve. Keflex nervous conditions are also recognized as 
being productive of inflammatory phenomena. An instance in point is 
the nervous irritation sometimes caused in the dental pulp by a misplaced 
uterus or the condition of pregnancy. Herpes zoster is an example of a 
pustular eruption following the course of a nerve, the inflammation being 
accompanied with infiltration of leucocytes around both the terminal 
branches and the trunk of the nerve. 

Inflammation is a process which may affect any tissue of the body 
having a vascular circulation or which is connected with blood-vessels. 
Enamel which has no vascular circulation and is in no way connected 
with blood-vessels cannot be the seat of inflammation. Dentin, which 
occupies a position midway between enamel and bone in the evolution of 
the calcareous tissues, presents conditions which are thought by certain 
authorities — Heitzmann, Abbot, Bodecker, and others — to be inflammatory 
in their nature, the peculiarities of the symptoms being due to the low 
state of vitality and the small percentage jot organic matter contained in 
its structure. 

Inflammation in vascular tissues usually begins with the phenomena of 
hyperemia, and progresses to exudation or to suppuration ; sometimes reso- 
lution takes place, at others leading to the production of new formations, 
or to metamorphoses of various kinds, or to devitalization and destruction 
of tissue, and creating a more or less serious disturbance of the functions 
of the parts. The inflammatory process may vary greatly in its character 
and in its location. 

The histologic character of inflammations depends upon two factors, — 
the nature of the exudation and the changes in the tissues. Both are used to 
classify the various forms of inflammation, according as the one or the 
other seems to be most pronounced. 

Exudation. — Exudation or diapedesis is the process by which during 
partial stasis of the blood- current the corpuscular elements of the blood 
(the leucocytes and phagocytes) and the liquor sanguinis pass through the 
walls of the blood-vessels into the tissue spaces beyond. This process is 
the result of changes in the vessel walls, which permit the passage or 
leakage of the elements of the circulating fluid- through the walls of the 
vessels. Ziegler says, ' i It may be accepted as an established fact that in 
inflammation the vessel wall is affected, but it is still questioned by some 
whether the affection is of the nature of a chemic alteration or a mere 



INFLAMMATION OF THE DENTAL PULP. 399 

widening of pre-existing intercellular spaces. ' ' Burden Sanderson believes 
"it is due to the loss of the power by the vessels of resistance to dilatation, 
and the loss of vital power, in consequence of which leakage takes place." 
Rupture or rhexis of the vessel walls sometimes takes place, which permits 
the red blood-corpuscles to escape into the tissues. 

Tissue Changes. — The cellular and fluid exudates which pass through 
the vessel walls collect first in their immediate neighborhood, but rapidly 
spread out and involve surrounding healthy tissue by occupying the 
lymph-spaces of the tissues. When this tissue infiltration is considerable 
it is liable to produce other disturbances of circulation and nutrition, 
and thus increase the area of the inflammatory exudation and tissue 
degeneration. 

Among the earliest changes which take place in the inflamed tissue is 
the coagulation of the fibrinous elements of the exudate, which prevents 
the further movement of the migrated corpuscles by enclosing them in the 
coagulated mass. 

One of the functions of the leucocytes is to take up solid particles and 
portions of broken down and disintegrated blood-corpuscles. Metchnikoff 
(1884) and his followers claim that they have also the power of englobing 
and destroying the invading pathogenic bacteria which have gained an 
entrance to the blood and other tissues of the body. And that by this 
phagocytic power of the leucocytes immunity was established in the 
organism. He found in certain observations made upon a species of 
daphnia, which is subject to infection by a torula resembling the yeast 
fungus that gains access to its body thrbugh its food, that the fungus 
penetrates the walls of the intestines and invades the tissues. In certain 
cases the infection was not fatal, and this he believed was due to the fact 
that the leucocytes which accumulated around the invading fungi seized 
upon these organisms, and eventually destroyed them. If the leucocytes 
were successful in overpowering the parasites, the animal recovered ; if 
not, the infection proved fatal. From this he argued that the pathogenic 
bacteria, when introduced into the body of an immune animal, are de- 
stroyed in a like manner, while they play an active part as prophylactic 
agents and in the metamorphosis of tissues and organs in inflammation. 

Metchnikoff explained that the leucocytes gathered up the bacilli and 
destroyed them by a process of internal digestion. This power of the 
leucocytes to destroy foreign substances was first suggested by Surgeon- 
General Sternbergh, of the United States army, in 1881. 

There is still a difference of opinion as to the power of the leucocytes 
to destroy living bacteria. Koch found in 1878 that the bacteria multiplied 
within the body of the leucocytes, and that many of these cells were de- 
stroyed by the bacteria. 

Sternbergh, Weigert, Baumgarten, and others, have maintained that the 
bacteria found in the leucocytes were already dead when taken up by these 
cells, their vitality having been destroyed by some agency outside of the 
leucocytes, namely the blood-serum, and that there is abundant experi- 
mental evidence to prove that the blood-serum has decided germicidal 
power. 



400 OPERATIVE DENTISTRY. 

Sternbergh says (1892), "Numerous experiments have been made during 
the past two or three years with the view of determining whether patho- 
genic bacteria are, in fact, destroyed within the leucocytes after being 
picked up by them, and different experimenters have arrived at opposite 
conclusions. In the case of mouse septicaemia, and in gonorrhoea, one 
would be disposed to decide, from the appearances and the arrangement 
of the pathogenic bacteria in the leucocytes, that they are not destroyed, 
but that, on the other hand, they multiply in the interior of these cells, 
which in the end succumb to this parasitic invasion. In both of the 
diseases mentioned we find leucocytes so completely filled with the patho- 
genic micro-organisms that it is difficult to believe that they have all been 
picked up by a voracious phagocyte which has stuffed itself to repletion, 
while numerous other leucocytes from the same source and in the same 
microscopic field of view have failed to capture a single bacillus or micro- 
coccus. Moreover, the staining of the parasitic invaders and the charac- 
teristic arrangement of the gonococcus in stained preparations of gonor- 
rhceal pus indicate that their vitality has not been destroyed in the interior 
of the leucocytes or pus-cells, and we can scarcely doubt that the large 
number found in certain cells is due to multiplication in situ rather than to 
an unusual activity of these peculiar cells. But in certain infectious dis- 
eases, and especially in anthrax, the bacilli included within the leucocytes 
often give evidence of degenerative changes, which would support the view 
that they are destroyed by the leucocytes, unless these changes occurred 
before they were picked up, as maintained by Nuttall and others." 

Nuttall (1888) has shown that the destruction of virulent micro-organ- 
isms in the blood of animals was not dependent alone upon the immediate 
presence of living leucocytes, but that the serum of the blood, when freed 
from all cellular elements of any kind, still possessed the power of de- 
stroying the vitality of bacterial forms equal to that of the blood in its 
normal state when all of its constituent elements were present. 

Buchner (1890) demonstrated that the serum was robbed of its germi- 
cidal properties by exposure to a temperature of 55° C. for half an hour. 
Its efficiency, on the other hand, was not impaired by alternately freezing 
and thawing it, but dialysis or extreme dilution with distilled water dimin- 
ished its germicidal power or completely destroyed it. If, however, it was 
diluted with an equal amount of water containing from 0.6 to 0.7 per cent, 
of sodium chloride, its germicidal action was in no way diminished. From 
this he concluded that the active agent in the blood which gave it this 
germicidal power is a living albumin, and that an essential constituent is 
sodium chloride, the removal of which, either by dialysis or dilution, 
robbed the blood of its germicidal power. These elements or constituents 
of the blood which possess the power of destroying pathogenic micro- 
organisms he termed "alexins." 

Han kin, Martin, and Ogatta (1891) have succeeded in isolating ferment- 
like "globulins," which in solution possess active germicidal powers. 

Later, Vaughn, Novy, and McClintock have found in their observations 
that the nucleins are the most important germicidal and protective agents 
possessed by the body ; that this bacterial constituent of the blood-serum 



INFLAMMATION OF THE DENTAL PULP. 401 

is not a serum albumin, but that it is a proteid, for it is destroyed at 
60° C. ; and that it is probably a nuclein, for it is not destroyed by gastric 
digestion. 

The nuclein which they isolated was found to possess most powerful 
germicidal properties when tested upon Koch's comma bacillus, the strepto- 
coccus pyogenes aureus, and the bacillus anthracis. 

If resolution now takes place the blood-current gradually resumes its 
natural flow, resorption of the exudates begins, the induration and swell- 
ing disappear, the pain ceases, and the tissues regain their normal color 
and functions. 

If, on the other hand, stasis becomes complete in a limited inflamed 
area, suppuration is established, first, by the death or necrosis of the exuded 
blood-cells and of the embryonal and fixed tissue-cells, — necrobiosis, — and 
secondly, by the liquefaction and complete dissolution of the tissue ele- 
ments, the leucocytes and embryonic cells formed from the fixed tissue-cells 
— phagocytes — being converted into pus-corpuscles and the intercellular 
substance of the tissues liquefied. 

Complete stasis occurring in larger areas may result in death of tissue 
en masse; when this occurs in soft tissues it is termed gangrene; wheu 
occurring in bony tissues it is termed necrosis. 

Another change which may take place in the inflammatory exudates is 
that of fatty degeneration. This is a process of retrograde change by which 
the albuminoid elements of the tissues and the exudates are converted into 
granular fatty matter. 

Pus, tubercles, etc., are sometimes converted into soft, cheese-like masses 
by a degenerative change known as caseation. 

Hyperplasias, or hypertrophies of tissue, are not uncommon sequelae of in- 
flammation. Hyperplasia is an increase of the elements which compose a 
tissue or an organ, resulting in an increase in the volume of the tissue or 
organ, and may be due either to over-stimulation, over-nutrition, irrita- 
tion, or a low form of inflammation. Polypus of the pulp, enlargement 
of an irritated gum festoon, and hypercementosis are examples of this 
condition. 

New formations resulting from inflammations are due to a proliferation 
of embryonic cells and their organization into new tissue, sometimes simi- 
lar in kind, but often of a different character from the tissue in which 
they originate, resulting in the formation of tumors of various kinds, 
some benign, others malignant. 

Examples of the former variety are the calcareous formations developed 
within the pulp-cavity ; and of the latter, good examples of the benign 
tumors are found in the fibromas which sometimes occur upon the gums, 
and the malignant varieties are well shown in osteosarcomas of the jaws 
and in epitheliomas of the lips. 

Inflammation is usually divided into two forms, — viz., acute and chronic, 
— and these again into many varieties, according to the anatomical location 
of the process, as taught by Virchow, such as catarrhal, fibrinous, paren- 
chymatous, phlegmonous, indurative, degenerative, scrofulous, and infec- 
tive. 

26 



402 OPERATIVE DENTISTRY. 

In acute inflammation the process runs a more or less rapid course and 
the symptoms are marked, while in the chronic form the symptoms are all 
less prominent, and any one or all of the cardinal symptoms may be so 
slightly developed as to escape notice altogether. A form between these 
two conditions has been denominated subacute inflammation. 

TABLE OF INFLAMMATORY PHENOMENA. 

Summary of steps : 

Traumatic 
Cliemic. 

1. Irritants. \ c. Bartoric or septic. 
cl. Electric. 
e. Thermic. 

2. Irritation. 

3. Determination or active hypertemia. 

4. Disturbance of circulation. 

5. Increased motion and retardation or oscillation. 

6. Stasis (partial). 

7. Vascular dilatation. 

8. Exudation, — diapedesis, rhexis. 

9. Swelling, — oedema. 

» | a. Vascularization. 

a. Resolution, or absorption or organization, "i &• Granulation. 

I c. Scar-tissue. 
h. Fibroid thickening or chronic inflamma- f Hyperplasia. 
10. Terminations. • tion. t New formations. 

c. Suppuration. 

d. Abscess, — necrosis. 
| e. Ulceration. 

If. Gangrene. 

INFLAMMATION OF THE PULP. 

Etiology. — Inflammation of the pulp may be either acute, subacute, 
or chronic in form, and each of these varieties may involve only a limited 
area of the pulp, when it is termed circumscribed inflammation, or it may 
involve the whole of the organ, when it is termed diffuse or general inflam- 
mation. 

Acute pulpitis is in a very large majority of cases due to exposure of the 
pulp, either from caries, fracture of the crown, mechanical abrasion, or 
erosion. About ninety-six per cent, of the primary cases, according to 
the records of the writer, are due to exposure from caries ; about three per 
cent, to fractures, abrasions, erosions, and other injuries of a traumatic 
nature involving a loss of tissue ; and one per cent, to constitutional con- 
ditions, such as plethora, pregnancy, nervous irritability, and kindred 
affections. 

These figures accord very closely with those of Tomes,* who says that 
' ' ninety-nine out of every one hundred cases are due to exposure of the 
pulp. 4 ' 



Tomes' s Dental Surgery, 4tb edition, p. 3S0. 



INFLAMMATION OF THE DENTAL PULP. 403 

In those cases which develop after the carious cavity has been filled, — 
secondary cases, — minute exposures of the pulp involving one of the cornua. 
— incomplete exposures, or pseudo-exposures, — which permit pressure to be 
exerted upon the pulp by reason of the thinness and decalcified condition 
of the wall of the pulp-chamber, and thermal shock aggravated by the 
presence of metallic fillings are the principal causes ; the latter, however, 
are the most prolific of inflammatory conditions, by reason of the fact 
that in incomplete and pseudo-exposures the pulp has generally been 
protected by some form of non-conducting capping, which in a measure 
prevents or lessens thermal shock in these cases. 

Exposure of the pulp to the fluids of the mouth permits the entrance 
of the pyogenic micro-organisms and establishes septic inflammation, which 
almost invariably terminates in suppuration. It is possible, however, for 
a septic inflammation to occur in the pulp without direct exposure of any 
part of this organ : first, by the penetration of the softened and decalcified 
dentin by the pyogenic or pus-producing micro-organisms which in their 
growth follow the dentinal tubuli, thus gaining access to the tissues of the 
pulp ; secondly, by the presence of these organisms in the blood, which 
have gained access to this fluid through some external wound or abrasion 
of the skin or mucous membrane, or from some pre-existing suppurating 
wound or abscess, forming secondary abscesses just as metastatic abscesses 
are formed in other portions of the body by the lodgement of these organ- 
isms in the capillary blood-vessels or glandular structures, forming a nidus, 
where, under favoring conditions of a weakened local vitality, they rapidly 
propagate. 

Pathology. — Inflammation of the dental pulp is in no way different 
from inflammation as observed in other connective tissues. It follows the 
same course, by the establishment of hyperemia, the exudation of leu- 
cocytes and their proliferation, the formation of infarcts, the escape of 
red blood-corpuscles, the coagulation of the fibrinous elements, and either 
resorption ending in resolution, the organization of the escaped cells 
into new tissue, the liquefaction of the exudates and the formation of 
pus, the death of the pulp en masse, followed by putrefaction — moist 
gangrene— and the formation of mephitic gases in those cases in which the 
pulp has been exposed to septic influences, or by mummification — dry gan- 
grene — in those cases in which the pulp has not been exposed to septic 
infections. 

Acute Circumscribed Pulpitis. — Acute circumscribed inflammation 
of the pulp is usually found in those cases in which the walls of the pulp- 
chamber has been perforated, exposing the surface of the pulp at this 
point to external irritating and septic influences. The area thus affected 
is sometimes very minute ; at others it involves a considerable portion of 
the surface of the pulp. The microscope reveals in the early stage of the 
inflammation a more or less extensive area immediately beneath the in- 
flamed surface, occupied by the inflammatory exudates, and smaller areas, 
which are colored red, the result of the formation of thrombi and infarcts 
and the escape of the red blood- corpuscles. 

Suppuration is later established upon the surface, and minute collec- 



404 OPERATIVE DENTISTRY. 

tions of pus-corpuscles may be found in the deeper structures of the 
organ. 

The character of the inflammation now depends upon the extent of the 
opening in the pulp-chamber, the activity of the phagocytes, and the 
dyscrasia or diathesis of the patient. When the perforation in the wall 
of the pulp-chamber is so small as to prevent a free escape of the pus 
which is formed at the point of exposure the suppurative inflammation 
becomes more acute, and the entire pulp is soon involved, ending in its 
speedy destruction. But when the perforation is so large that the pus 
formed upon the surface finds a ready exit, the suppurative process is apt 
to be prolonged for an indefinite period, the character of the process be- 
coming subacute or chronic in its manifestations with the formation of an 
ulcerating surface. 

On the other hand, if the patient is of a scrofulous, tuberculous, or 
syphilitic diathesis, or is suffering from malaria, diabetes mellitus, or albu- 
minuria, the suppurative inflammatory process will run a rapid course, 
ending in a few days at most in the destruction of the pulp ; while if the 
individual is in fair health and of good constitution, the tendencies are 
towards resolution or a subacute or chronic inflammation. 

Acute Diffuse or General Pulpitis. — Acute diffuse or general inflam- 
mation of the pulp is the most common result of all forms of irritation of 
whatever nature, whether mechanic, chemic, septic, or nervous. It may 
occur, as already pointed out, with or without perforation of the pulp- 
chamber. 

The character of the inflammation is such that it speedily causes stasis 
of the blood-current by general infarction or thrombosis, unless the per- 
foration in the wall of the pulp-chamber is sufficiently large to permit 
expansion or swelling of the tissues to a degree that will relieve the press- 
ure upon the blood-vessels at the apical end of the pulp-chamber. 

The result of general infarction is death of the pulp en masse. Inflam- 
mation, however, both acute, circumscribed, and diffuse, may be induced by 
infarcts in limited areas within the body of the pulp, caused by intense 
hypersemia, as pointed out by Black.* Extravasation of red blood- corpus- 
cles and their disintegration frequently occurs as a result of infarction. 
The disintegration of these corpuscles and the dissemination of their col- 
oring matter through the substance of the dentin explains the pinkish hue 
which often obtains after the death of the pulp, and which, from the grad- 
ual decomposition of the hseinoglobin thus disseminated, progressively 
changes the color of the dentin to brown, blue, and blue-black. 

Symptoms and Diagnosis. — The symptoms of acute pulpitis must be 
studied from two aspects : first, those cases in which there is no exposure 
of the pulp 5 second, those which present exposure and are necessarily 
septic. The symptoms of inflammation of the pulp are so nearly like 
those of hypersemia that differentiation between them becomes extremely 
difficult. Black thinks that in pulpitis the pain is less paroxysmal and 
more inclined to be prolonged. 

* American System of Dentistry, vol. i. p. 846. 



INFLAMMATION OF THE DENTAL PULP. 405 

On account of the unyielding nature of the walls of the pulp-chamber 
the symptoms of acute pulpitis are generally active and violent, and are 
characterized by sharp, stinging, lancinating, throbbiug pain, at times 
continuous ; in other cases the pain may be paroxysmal in character, in- 
creasing in intensity until it becomes almost unbearable, then slowly sub- 
siding, the exacerbations occurring with short intervals of a few minutes 
or with larger intervals of an hour or two. In those cases presenting with- 
out exposure of the pulp the inflammation runs a rapid course, and the 
vitality of the pulp may be destroyed in a few hours from venous conges- 
tion, terminating in complete stasis, induced by pressure upon the arteries 
entering the apical foramen. In those presenting exposure of the pulp, 
the inflammatory symptoms may be prolonged for several days, and finally 
end in complete stasis and death en masse by the same mechanic obstruc- 
tion to the circulation, or the inflammatory symptoms may assume a chronic 
form and be prolonged indefinitely. Exercise or the recumbent position 
increases the violence of the pain in the acute form of inflammation, as 
does also excessive changes in the temperature, pressure from foreign sub- 
stances in the cavity, or the irritation from sweets, acids, or salt. 

In those cases where there is no exposure of the pulp the symptoms are 
usually most severe but brief in their duration, and they are much less 
liable to suppuration or decomposition by reason of the exclusion of the 
micro-organisms from external sources. 

On the other hand, in those cases presenting an exposure of the pulp, 
the symptoms are generally less severe, but are more prolonged, the course 
of the inflammation being modified by the opportunity for expansion and 
protrusion of a portion of the pulp — hernia — under the pressure of the 
distended blood-vessels, which is made possible by the break in the con- 
tinuity of the walls of the pulp- chamber. 

The exposure of the pulp to the influence of the septic conditions of the 
carious cavity and of the secretions of the mouth introduces a complication 
which renders any attempt at conservative treatment much more difficult 
than would be the case if micro-organisms from external sources had not 
come in contact with it. 

The break in the continuity of the walls of the pulp-chamber causes 
another complication which often greatly aggravates the suffering endured 
in acute inflammation by permitting the pulp, which is often greatly 
distended with blood, to press upon the sharp and irregular edges of 
the perforation, producing strangulated hernia of the pulp. Belief is 
only obtained after depleting the organ by puncturing or scarifying its 
surface. 

Prognosis. — The prognosis of acute pulpitis has generally been con- 
sidered as extremely problematic, and therefore efforts at conservation of 
the organ under such conditions have never received much support from 
the profession at large. That the dental pulp may under the favorable 
circumstances of good general health and hygienic surroundings finally 
recover from acute inflammation which has not progressed to the stage of 
suppuration there is not the least doubt, as can be attested by numerous 
cases and the clinical experience of many operators. And yet the fact 



406 OPERATIVE DENTISTRY. 

remains that in many of these seeming cases of recovery supplementary 
pathologic changes have occurred, usually of a degenerative type, like 
calcareous deposits or fatty metamorphosis, which have finally, after 
months, or perhaps years, terminated in devitalization and decomposition, 
or dry gangrene. 

Treatment. — The treatment of acute pulpitis may be both local and 
systemic, As a rule, however, local treatment will usually be sufficient to 
control the symptoms, but when these measures fail, as occasionally hap- 
pens, systemic treatment may prove of inestimable value. 

Local treatment consists in first freeing the carious cavity from all foreign 
substances and irrigating it with an alkaline solution, like soda bicarbonate, 
one drachm, tepid water, one fluidounce, to neutralize the acid condition of 
the disorganized dentin. The cavity is then dried and the same local meas- 
ures employed as indicated in the treatment of hyperemia of the pulp. . The 
most efficient means which can be employed to give relief in those cases 
complicated with exposure of the pulp is depletion by direct puncture or 
incision of the exposed organ. Cocaine hydrochlorate — ten to twenty- 
five per cent, solution — should be applied to the pulp after adjusting a 
rubber dam, and in from two to five minutes the pulp will have been suffi- 
ciently anaesthetized upon the surface to permit of its puncture or incision 
without pain. Chloretone solution, made by mixing equal parts by weight 
of ether and chloretone, may be applied to the exposed pulp upon a 
pledget of cotton for the same purpose. After the vessels have been de- 
pleted the pulp may be dressed with some efficient sedative and antiseptic 
remedy like the following : morphine sulphate, one-tenth grain, atropine, 
one-hundredth grain, dissolved in a drop of oil of cloves. The hypodermic- 
tablets of morphine and atropine in these proportions can always be pro- 
cured and kept on hand ready for use, and may be prepared for applica- 
tion to the cavity by first crushing the tablet upon a glass or porcelain 
mixing-slab and then adding a drop of oil of cloves. It is then gathered 
upon a pledget of cotton, placed in the bottom of the cavity, and sealed 
in with zinc oxyphosphate, mixed thin, and inserted in this condition, so 
that no pressure will be brought to bear upon the exposed pulp. Tempo- 
rary stoppings which permit the percolation of the septic oral secretions 
through or around them should be avoided, as success in the treatment of 
these cases will depend largely upon maintaining aseptic conditions of the 
cavity and the pulp. Another efficient remedy for relieving the pain in 
acute pulpitis is a paste made of cocaine hydrochlorate in glycerol, ap- 
plied as above. Saturated solutions of menthol and thymol are also 
recommended for the same purpose. 

Another method of relieving the congested condition of- the pulp is the 
abstraction of blood from the engorged veins and capillaries of the gums, 
directly over the affected tooth, by scarification, and promoting the flow 
of blood by the application of warm water held in the mouth. The ab- 
straction of blood by the application of leeches is an old method, and still 
advocated by some authorities. The dangers from infection, however, are 
so great from the use of this method that its application is inexcusable in 
these days of enlightened aseptic surgery. 



INFLAMMATION OF THE DENTAL PULP. 407 

Counterirritation is sometimes useful in relieving the congestion of the 
vessels of the pulp by drawing the blood to the surface. This may be 
accomplished by the continued use of capsicum plasters applied to the 
gum over the affected tooth ; painting the gum with tincture of aconite 
and tincture of iodine, equal parts, or by drying the gum and painting it 
with cantharidal collodion, which raises a blister. Care should be taken 
to paint only a small area, as the irritation induced by the blister renders 
the gum very sensitive for several days. 

Systemic treatment consists of the administration of general sedative and 
analgesic remedies. Ten grains of Dover's powder administered at bed- 
time, or five to ten grains of antikamnia, or ten grains of ammonol, will 
usually insure a quiet night. A hot foot-bath just before retiring may be 
supplemented with advantage, as this is a useful means of equalizing the 
circulation and relieving arterial tension in the upper portion of the body. 
A brisk saline cathartic is also a valuable additional means of relieving 
the determination of the blood to the affected part. 

After the inflammatory symptoms have been relieved and the pulp 
becomes quiescent, the question of the after-treatment must be settled, — 
viz., whether conservation shall be attempted or the pulp devitalized. The 
settlement of this question calls for a clear insight into the local and con- 
stitutional conditions which surround the case, and good judgment is 
required in the final decision, for if the operator would render his patient 
the best possible service in each individual case he must be free from all 
bias or prejudice and ready to act as his best judgment dictates. 

SUPPURATION OF THE DENTAL PULP. 

Definition. — The term suppuration comes from the Latin suppuratio, 
from suppurare, to form pus. The formation of pus. 

Suppuration is the most frequent termination of acute inflammation. 
An inflammation which terminates in this manner is termed suppurative 
inflammation. 

Suppuration is a process by which the morphologic elements found in 
the inflammatory exudates— the leucocytes and the embryonic cells formed 
from the fixed tissue-cells — are converted into pus-corpuscles and the in- 
tercellular substance of the tissue is liquefied. 

The conversion of the leucocytes and embryonic cells and the liquefac- 
tion of the intercellular substance to form pus are produced by a peculiar 
peptonizing or digestive action of the pyogenic micro-organisms. 

The causes of suppuration may be divided into indirect and direct. 

The indirect causes of suppuration are the inflammatory phenomena of 
exudation, the crowding of the connective-tissue spaces with the corpus- 
cular elements of the blood, and the consequent pressure upon the capillary 
blood-vessels, resulting in complete stasis and death of the tissues involved. 
Death of the tissues, however, is not always necessary to produce suppu- 
ration, but the changes which take place in the affected parts are those 
which are expected to follow intense irritation, — viz., hypersemia, exuda- 
tion, coagulation of the fibrinous elements, and partial stasis. 

The direct causes of suppuration are certain specific micro-organisms — 



408 



OPERATIVE DENTISTRY. 



the pyogenic bacteria — and their peptonizing effect npon the leucocytes, 
embryonic cells, and intercellular substance of the tissues. 

In the suppuration due to the presence of the pyogenic bacteria — in- 
fectious inflammations — the direct cause which produces it multiplies in 
the tissues. Consequently its tendency is to become progressive, while 
from the pus produced by this form of inflammation the pathogenic micro- 
organisms — the staphylococci and streptococci — can be cultivated, and if in- 
troduced into another organism will produce inflammation and suppuration. 

Pus may be produced, however, under certain circumstances without 
the presence, aid, or intervention of micro-organisms, as, for instance, 
by the introduction beneath the skin of certain irritating chemical sub- 
stances. Councilman was the first to prove the fact that croton oil when 
injected beneath the skin of rabbits would produce suppuration without 
the action of micro-organisms. The early experiments in this line gave 
very conflicting results. Some investigators succeeded in producing an 
aseptic pus which would not cause suppuration when introduced into 
another organism, while others produced a septic product with the same 
chemic agent. These conflicting results were due in some cases to imper- 
fect aseptic methods ; in others to the fact that the same chemic substance 
would produce suppuration in one species of animal and not in another, 
as pointed out by Christmas, who was unable to produce suppuration in 
rabbits with turpentine or mercury, but succeeded with dogs. 

Fig. 502. 




Suppuration of the dental pulp is in nowise different from suppuration as 
observed in other connective tissues, except that which relates to its loca- 
tion and peculiar environment. It is found most commonly associated 
with exposure of this organ and under large fillings, the pulp of the tooth 
having been previously inflamed. 



INFLAMMATION OF THE DENTAL PULP. 



409 



Fig. 503. 



hmm 



Suppuration of the pulp presents in two forms, superficial and paren- 
chymatous, and may be either acute or chronic in its manifestations. 

Acute superficial suppuration of the pulp, or ulceration, is a destructive 
loss or solution of continuity of the exposed surface of the organ ; a molec- 
ular death of tissue, which will not permit of repair by primary union, 
and owes its existence to the fact that the retrograde changes or metamor- 
phoses are in excess of those of repair. Change the relationship between 
these conditions and the ulceration will heal by granulation, just as is seen 
in ulcerations upon the free surfaces of the body. If unchecked, the 
ulcerative process tends to gradual but final destruction of the whole organ. 

Fig. 502 shows a section by Black 
taken from an inflamed area. The 
blood-vessels are represented as empty 
to bring them more prominently into 
view, but in reality they are filled with 
coagulated blood. It will be further 
noticed that the normal cells have 
nearly all disappeared, and that their 
places have been occupied by the in- 
flammatory products of exudation. 
Opposite the point of exposure («) the 
odontoblastic layer has been destroyed 
and a pus-pocket formed in the deeper 
substance of the pulp, while at b the 
odontoblastic layer has been consider - 
. ably undermined. This undermining of 
the odontoblastic layer Dr. Black found 
to be the general rule in progressive 
suppuration or ulceration of the pulp. 

Fig. 503 represents a longitudinal 
section taken from a case of pro- 
gressive suppuration or ulceration of 
the pulp of an incisor, and shows that 
the destructive process follows the 
course of the veins, progressively de- 
stroying the tissue as it advances from 
the point of exposure to the apex. 

Acute parenchymatous suppuration 
of the pulp, or abscess, is an accumula- 
tion of pus in the parenchyma of the 
organ surrounded by a wall of lymph. 
It owes its existence to the action of 
an excessive and continuous irritation 
which has caused a copious exudation, 
the filling of the connective- tissue 
spaces, pressure upon the capillary 

blood-vessels causing stasis, followed by coagulation of the fibrinous ele- 
ments. The leucocytes lose their vitality, while pressure upon the con- 




Progressive suppuration of the pulp. (After 
Black.) X 100. a, healthy tissue; &, odonto- 
blastic layer; c, inflamed tissue showing di- 
lated veins; d, line of demarcation of suppu- 
rative process ; e, pus. 



410 



OPERATIVE DENTISTRY. 



nective-tissue cells involved in the affected area produces a like result in 
them, and by the action of the pyogenic bacteria which have gained access 
through external channels, or through the avenue of the circulation, the 
exudates and the tissues are converted into pus. These abscesses are usu- 
ally situated near the point of exposure, and are rarely found singly. 
Black says it is not uncommon to find several minute pus-pockets at a 
little distance from the point of exposure. The abscess may, however, 
occupy the central portion of the pulp. Burchard removed such a pulp, 
the abscess involving nearly its entire structure, but leaving the peripheral 
portion unbroken, as shown in Fig. 504. 

Fig. 504. 




Transverse section of pulp of inferior bicuspid, partly diagrammatic. (After Burchard.) 
cavity ; 6, embryonic cells at periphery of abscess cavity ; c, occluded blood- 



Black has found abscesses in the deeper structures of the pulp, most 
frequently in the molars. Fig. 505 shows such an abscess in a central in- 
cisor, about midway of its length, the coronal portion of which was sup- 
purating, while the evidences of inflammation within the deeper structures 
was rather more extended than is common. 

Suppurative inflammation of the pulp under cappings and large fillings 
used to be a frequent occurrence before the introduction of antiseptics in 
the treatment of surgical wounds. To-day, however, such occurrences are 
much more rare by reason of the improved methods of treatment which 
have been based upon this great scientific discovery. 

Symptoms and Diagnosis. — The formation of an abscess in the soft 
tissues of the body causes considerable swelling, and when the swelling is 
hindered by overlying and unyielding fascia the pain becomes very intense, 
and the pus burrows along courses which offer the least resistance, often 
forming long and tortuous channels in the effort to reach a point of exit. 

In suppuration of the pulp with a minute perforation of the wall of the 
pulp-chamber, or under a capping or a large filling, the pus is held back, 
and as it accumulates, causes pressure upon the tissues of the pulp, which 



INFLAMMATION OF THE DENTAL PULP. 411 

either give way or are destroyed. The pain which is induced by this pro- 
cess is different from that caused by hyperemia, in that the onset of the 
attack is not so sudden nor so violent. It begins with a dull, heavy, gnaw- 
ing sensation, which gradually increases in intensity to the most violent 
and almost unendurable pain. The duration of the pain is governed by 
the amount and rapidity with which the pus is formed. Sometimes the 
accumulation of the pus is so rapid that the vitality of the pulp is destroyed 
in a few hours ; at others devitalization may not occur under -twenty-four 
to forty-eight hours. Death of the pulp is induced by the pressure upon 
the apical blood-vessels, causing general infarction. Evacuation of the 

Fig. 505. 




within the tissues of the pulp. (After Black.) V 250. The field includes about one-half of 
the little pocket of pus. 

pus by opening the pulp-chamber gives almost instant relief from the 
severe symptoms. Sometimes when the pus is deep-seated it becomes 
necessary to puncture the abscess with a probe. The amount of pus which 
is occasionally contained in a pulp-chamber is surprisingly large, at times 
welling up in such quantity as to nearly fill a large cavity of decay. The 
pressure under such circumstances must have been very considerable in- 
deed, and thus accounts for the intense character of the pain. In from six 
to twenty-four hours after the cessation of the pain symptoms of apical 
irritation begin to be manifest unless the pulp-chamber has been opened 
and the pus is evacuated. 

The presence of small abscesses within the parenchyma of the pulp are 
not always productive of severe pain, and they may be retained for an 
indefinite period, and finally absorbed. (Black.) 

Accumulations of pus within the pulp may, as in other locations of the 
body, undergo fatty degeneration, as pointed out by Salter. Decomposi- 
tion of the retained pus may take place with the generation of niephitic 
gases. Black says upon this point, ' l Warm liquids when taken into the 
mouth should increase the pain by expanding the gases, while cold would 
relieve it by the opposite effect." This is a diagnostic fact of considerable 



412 OPERATIVE DENTISTRY. 

importance, and should always be borne in mind in diagnosing the various 
forms of acute pulpitis. 

Treatment. — The treatment of this class of cases requires the im- 
mediate opening of the pulp-chaniber, the evacuation of the pus, and anti- 
septic treatment of the suppurating pulp. Although it is possible under 
favorable circumstances to control the suppurative process and relieve the 
inflammatory symptoms, efforts at conservation of the pulp are not favor- 
able, for the reason that they so rarely succeed. It is, therefore, the wiser 
plan to devitalize the pulp and remove it as soon as the inflammatory 
symptoms are under control. 

CHRONIC INFLAMMATION OF THE DENTAL PULP. 

Chronic pulpitis is usually a sequel of the acute form of inflammation, 
but it may occasionally be due to a low grade of irritation which has never 
been of sufficient severity to produce other than a mild but continuous 
hyperemia of its blood-vessels, such an irritation as would accompany the 
gradual wearing down of the teeth from mechanic abrasion or chemic 
erosion with the formation of secondary deposits, as already pointed out 
in Chapter XXII. 

Chronic pulpitis, which is the sequel of the acute stage, may present 
itself in either of three common forms, — viz., chronic suppurative inflamma- 
tion, hypertrophic inflammation, and degenerative inflammation. 

Chronic suppurative inflammation of the pulp is almost always confined to 
the surface of the pulp in connection with perforations of the wall of the 
pulp -chamber, which are small or moderate in extent, but which allow of 
the free escape of the pus as rapidly as it forms. If for any reason the 
accumulations of pus are retained, active symptoms usually supervene, 
and acute abscess of the pulp is the result. 

Chronic suppuration of the pulp tends sooner or later to cause its de- 
struction either by molecular death (ulceration) and devitalization of its 
tissue, or by death en masse (gangrene) of extensive portions and sloughing 
of the gangrenous areas. Severe pain is rarely present in this form of in- 
flammation, unless the opening into the pulp-chamber becomes stopped up 
with food dSbris, or the cavity is filled with a septic dressing. The removal 
of these obstructions to the escape of the pus gives immediate relief. 

The heat sense is greatly lessened, as is also its general sensitiveness to 
chemic irritants and to pressure or instrumentation. 

The only reliable treatment in this form of inflammation of the pulp is 
devitalization and extirpation. Conservative treatment based upon the 
possibility of the suppurating surface becoming cicatrized and the pulp 
being capable afterwards of performing its normal functions rests upon 
such meagre clinical evidence that it cannot be recommended except as a 
purely experimental study. 

Hypertrophic inflammation, or polypus of the pulp, can occur only when 
the walls of the pulp-chamber have been perforated to a considerable extent, 
for when they are intact there is no possibility of enlargement, by reason 
of the fact that there is no room in the pulp-chamber for such growth. 

The size of the perforation in the walls of the pulp -chamber determines 



INFLAMMATION OF THE DENTAL PULP. 413 

to a certain extent the size and the character of the new growth. In small 
perforations the pulp protrudes but slightly, except when acute inflam- 
matory symptoms are present, as already indicated upon a previous page. 

When the perforation in the wall of the pulp-chamber is large, the pulp 
may bulge from the opening, forming a large fleshy mass {polypus of the pulp), 
which may be so large as to fill the entire cavity of decay, and even pro- 
trude beyond it. This condition is more commonly seen in young persons 
at the period of adolescence and in scrofulous and tuberculous individuals. 

In the early stages of the growth or hypertrophy of this tissue it is very 
sensitive, but later, as it increases in size, it gradually becomes less and less 
sensitive until, comparatively, it is no more sensitive than the gum-tissue. 

The hypertrophied mass is composed of vascular distentions, granula- 
tion-tissue, and connective-tissue fibres, the whole mass being covered with 
a thick epithelium. In general appearance it is so like gum-tissue that it 
is with extreme difficulty that it can be distinguished clinically from that 
tissue. It may be differentiated from a gum festoon which has grown into 
the cavity of decay by the fact that it is connected to the pulp by a narrow 
constricted pedicle, and that a probe can be made to pass beneath it and 
completely around the whole circumference of the cavity of decay, while 
a gum festoon which occupies the cavity can be lifted out, and will be found 
to be connected with the gum at the cervical margin by a broad pedicle. 

Hypertrophied tissue will be found to be quite difficult to destroy with 
arsenic or other escharotics. Before attempting devitalization the mass 
should be amputated at the bottom of the cavity by severing the narrow 
pedicle, and as soon as hemorrhage has ceased arsenic may be applied 
to the stump and the case treated as an ordinary exposure. 

Calcification of an hypertrophied pulp has been known to occur. 
Tomes * mentions a case reported by Eogers, in which hypertrophy of a 
pulp took place after the crown of an upper molar tooth was removed in 
an unsuccessful attempt to extract it, leaving the pulp exposed. Some 
months afterwards the roots were removed, and the hypertrophied pulp was 
found to have extended over the sharp edges of the pulp-chamber and to 
be completely calcified. Black f described a somewhat similar case occur- 
ring under a metallic capping, and Heider and Wedl I figure a case in their 
atlas of a similar condition occurring in an incisor tooth of an antelope. 

Another result of hypertrophic inflammation of the pulp is the re- 
sorption of the dentin surrounding the pulp, causing enlargement of the 
pulp-chamber. Such conditions are, however, very rarely met with in 
clinical practice. Black mentions a case of this character occurring in a 
first lower molar which he had capped for exposed pulp ten years before 
and had inserted a large gold filling. Irritation of the pulp had persisted 
for the last two or three years. On removing the filling the pulp-chamber 
was found to be enormously enlarged, and an opening to the peridental 
membrane had occurred at the bifurcation of the roots. 



* Tomes' s Dental Surgery, 4th ed., p. 367. 

t American System of Dentistry, vol. i. p. 859. 

t Atlas of Pathology of the Teeth. 



414 



OPEKATIVE DENTISTRY. 



In another case, a central incisor, the enlargement of the pulp -chamber 
Avas not so great, but was unmistakable. 

The writer saw a similar case in consultation with the late Dr. W. W. 
Allport, occurring in a first superior bicuspid, the pulp of which, accord- 



Fig. 506. 



Fig. 507. 





Pulpitis. ( After Bodecker.) X 300. S, second- 
ary dentin; B, bay-like excavations filled with 
medullary or inflammatory corpuscles ; M, mul- 
tinuclear body ; V, blood-vessels in 
section. 



ing to the record, was not exposed 
when the tooth had been filled five 
years before, but which was found 
upon removing the filling not only ex- 
posed, but the pulp-chamber was en- 
larged to more than twice its normal 
size. This case occurred in a lady 
aged about forty, who had been suffer- 
ing for more than a year with reflex 
neuralgia and dimness of vision which 
threatened blindness. 

Pig. 506 is made from a photograph 
of a superior central incisor in the pri- 
vate collection of the writer, and shows 
the pulp-chamber greatly enlarged. 

Bodecker * presents a figure illustrating the resorption of secondary 
dentin (Fig. 507), which seems to indicate the manner in which resorption 
of the dentin forming the walls of the pulp-chamber takes place in this 
class of cases. At M will be noted a large multinucleated cell (giant 
cell) which has invaded the area of resorption and is evidently performing 
the function of the odontoclasts by removing the dentin. 

Degenerative inflammation of the pulp, involving structural changes in the 
tissues, is usually caused by a long-continued and low form of inflamma- 
tion, such as would be likely to be produced by a pseudo- or by an incom- 
plete exposure of the pulp, or by a puij)-capping. The most common form 
of degeneration of structure is atrophy of all the normal elements of the 
pulp except its fibrous tissue, which becomes greatly increased in amount, 
forming areola which are filled with fluid. (Black.) The changes in the 
structure usually take place at or near the point of exposure, but they are 
not always confined to this location. The bulb of the pulp suffers most, 
while the balance of the organ may appear to be in a more or less normal 
condition. Fig. 508 illustrates this condition, and was made from the bul- 
bous end of the pulp of a tooth which was the subject of pyorrhoea alveolaris. 



Morphology and Histology of the Dental Tissues, p. 645. 



INFLAMMATION OF THE DENTAL PULP. 



415 



Black* says of this affection, "The original cells of the pulp for the 
most part disappear or lose their nuclei and become converted into very 
fine fibres. Areola develop in the matrix, and all the histologic characters 
of the tissue are profoundly changed." 

Fig. 508. 






Section of d 



Bulbous end. Fibrous dege 



Arkovy has described this affection as reticular atrophy of the pulp. 
Black found in his studies of this condition every possible grade of change, 
from an occasional appearance of areolae to complete areolation of large 
portions of the pulp. He thinks it is possible that the oedema noticed in 
the affection may be the result of hyperemia which has produced effusion, 
and yet in all the cases examined he found the evidences of inflammatory 
action unmistakable. 

The symptomatology is not well marked, although the sensitivity of the 
organ is greatly diminished to all the tests applied. 

Treatment. — The only treatment that can be recommended is devi- 
talization of the pulp and its extirpation. 



American System of Dentistry, vol. i. p. 859. 



CHAPTEE XXV. 

EXPOSURE OF THE DENTAL PULP AND ITS TREATMENT. 

Exposures of the dental pulp are either the result of caries or of trau- 
matic injuries of an accidental nature which produce a loss of tissue by 
fracture, thus uncovering the pulp, or as a result of surgical injury in the 
preparation of the cavity to receive a filling*. 

Deep-seated caries is the most common cause of exposure of the pulp. 
By the processes of decalcification and disintegration of the dentin it 
sooner or later exposes the pulp and renders it subject to painful irritation, 
hypereemia, inflammation, and finally devitalization. 

In the consideration of the subject of pulp exposure from caries and 
traumatic injuries it may, for the convenience of description, be divided 
into three stages or degrees, — viz. : 

Pseudo-exposure. 

Incomplete exposure. 

Complete exposure. 

Pseudo-exposure, or false exposure of the pulp, is that condition which 
prevails when the carious process has so far progressed as to have nearly 
reached the pulp, leaving only a thin layer of partially decalcified and 
infected dentin to protect it from mechanical injury, but which is, how- 
ever, more or less readily penetrated by the oral secretions, the bacteria of 
the mouth, the soluble chemic substances which enter the mouth in the 
form of food, condiments, and medicines, and by the influence of changes 
of temperature of even a moderate degree. 

These irritating influences often render the pulp highly sensitive, and 
cause it to respond very acutely whenever they are brought to bear upon 
it through the carious cavity, while if prolonged, they end, sooner or later, 
in inflammation and finally death of the pulp. 

A traumatic injury which nearly exposes the pulp, leaving the pro- 
tecting surface so thin as to cause the pulp to respond painfully to the 
above-mentioned irritating agencies, should be classed as a pseudo- 
exposure. 

The pain which is produced by active hyperemia is generally acute and 
paroxysmal in character, but, as a rule, is only of a few minutes' duration. 
It comes on most frequently while eating, especially sweets and acid fruits, 
or drinking hot or very cold fluids, or breathing very cold air. If the 
pulp becomes infected with the pyogenic organisms, efforts to conserve its 
vitality will usually prove futile. 

Treatment. — Two methods may be employed in the treatment of 
pseudo-exposure of the pulp, — viz., conservation and devitalization. 

Conservation. — Conservative treatment of the pulp should in these 
cases be employed under all circumstances which present a fair prospect of 

416 



EXPOSURE OF THE DENTAL PULP AND ITS TREATMENT. 417 

maintaining the organ in a normal condition. The pulp being the organ 
which supplies nutrition and sensation to the dentin, its vitality should for 
these reasons be carefully i:>reserved, while, upon the other hand, after the 
vitality of the pulp has been destroyed, the tooth loses its translucency, be- 
comes more or less discolored and brittle, presents a greater susceptibility 
to caries, and is liable to periodic attacks of pericemental irritation from the 
decomposition of the organic elements of the dentin, while occasionally the 
pericemental irritation may increase in severity or become chronic, resulting 
finally in the loss of the tooth. It therefore becomes for the latter reasons 
also very important that the vitality of the pulp should be preserved 
whenever it is possible to do so. Certain operators have, on the other 
hand, advocated the conservation of the pulp in all cases. Witzel advo- 
cates conservative treatment of even small portions of the living pulp re- 
maining in the canals, and Belisario and Henry advocate the same course. 

Devitalization should be practised only as a dernier ressort. The writer 
is aware that this teaching is in opposition to some very good authorities, 
who have frequently stated ' ' that when a tooth has been fully formed it 
has no further need of the pulp, and it may, therefore, be destroyed with- 
out damage to the integrity of the tooth ;' ' but he, nevertheless, desires in 
these pages to enter a protest against such teaching, and against the prac- 
tice of destroying by wholesale dental pulps which he believes could, with 
the same degree of care and skill exercised in their devitalization, have 
been preserved to fulfil their normal function for many years, or even for a 
lifetime. 

Opening the Cavity. — In the opening of the cavity and the excava- 
tion of the disintegrated dentin great care should be exercised not to 
expose the pulp. The relations of the pulp-chamber and of its cornua 
must be kept constantly in mind, and even then it may be that by an un- 
lucky sweep of the excavator or an excessive prolongation of the pulp 
cornua the pulp-chamber may be entered and the difficulties of the con- 
servation of the pulp thereby greatly increased. 

After all of the disintegrated and decalcified tissue has been removed 
— and this should not be commenced, for prudential reasons, until the 
rubber dam has been adjusted — the cavity may be carefully wiped with au 
efficient antiseptic, like the oil of cloves, oil of cassia, oil of peppermint, or 
carbolic acid, ninety-five per cent. The surface of the cavity lying nearest 
to the pulp should then be carefully scrutinized with a magnifying lens for 
the slightest exposure of the pulp or of its cornua, and if the integrity of 
the pulp-chamber is found to be intact, the pulp may be protected from 
pressure and thermal shock by the interposition of a rigid and non-con- 
ducting material — that will possess no irritating qualities — between the 
bottom of the cavity and the filling. 

Temperature Sense. — The u temperature sense," as shown by Dr. 
Louis Jack,* varies greatly in different individuals, and this fact must 
always be taken into consideration in all efforts of conservative treatment 
of the pulp. 

* Dental Cosmos. January, 1899. 

27 



418 OPERATIVE DENTISTRY. 

Dr. Jack has found that the variation in the heat- rate stands, in normal 
teeth, between 120° and 135° F., while the normal cold-rate varies 
between 40° and 70° F. 

The teeth of each person seem to possess an individual tolerance of a 
certain degree of heat and cold which will not produce pain, but whenever 
these limits are passed pain is the result. The average range of tolerance- 
was found to vary between forty-eight and seventy-five degrees. It there- 
fore becomes evident that if the vitality of the pulp is to be preserved in 
this class of carious teeth the pulp must be thoroughly protected against 
any degree of temperature that might cause irritation. 

Dr. Jack also observed that marked intolerance to degrees of tempera- 
ture that are within the average normal range indicated a serious condi- 
tion of the pulp, and that after the pulp had been protected for a time 
from thermal shock, the temperature range gradually increases until 
normal tolerance is reached. 

Materials for Capping, — Gutta-percha is, perhaps, by reason of its 
non-conducting cpaalities, the very best material that can be used for the 
purpose of protecting the pulp against thermal shock. The cavity may be 
entirely filled with it, or it may be used as a simple non-conducting lining, 
and the balance of the cavity filled with zinc oxyphosphate cement. 
Metal fillings should never be introduced into such cavities until the normal 
tolerance to heat and cold have been restored. The metallic filling may be 
inserted after removing a portion of the gutta-percha or cement. Its entire 
removal and substitution of a metal filling often proves disastrous to the 
vitality of the pulp. Such teeth can be made, however, more comfortable 
by the insertion of porcelain inlays than by metallic fillings, as the porce- 
lain is a poorer conductor of caloric than the metals. 

Zinc oxysulphate cement to which a drop or two of oil of cloves has 
been added is frequently used as a capping or protector of the dental 
pulp because of its non- irritating and non-conducting properties. 

Whenever the layer of dentin covering the pulp is very thin and there 
is danger of producing pressure upon it in packing the filling, or from the 
pressure of mastication, a metallic cap may be employed (Fig. 509), or one 
may be fashioned from sheet lead or tin. The 
/n! metal should be so concaved that when it is 

@ ® ® |) 3 J) 3 placed in position in the cavity it will touch only 
at its edge. To protect the pulp from thermal 
shock and to secure the cap in position thick zinc oxysulphate may be 
flowed upon the bottom of the cavity, the cap placed in this and covered 
with a layer of the same material or of gutta-percha stopping, — after the 
cement has set, — and the balance of the cavity filled with zinc oxyphos- 
phate. 

Zinc oxy chloride cement is sometimes used as a palp capping, but the 
dangers of irritation and devitalization due to the irritating and escharotie 
action of the zinc chloride has caused it to be looked upon as an unsafe 
material to employ when the conservation of the pulp is the object in 
view. It was formerly employed to a considerable extent not only in the 
treatment of such cases as are now under consideration, but in cases of 



EXPOSURE OF THE DENTAL PULP AND ITS TREATMENT. 419 

actual or complete exposure of the pulp, and statements were made by 
enthusiastic operators as to its wonderful conserving effect upon the pulp ; 
but a few years later it was discovered that the term preserving better 
suited the condition which resulted from its application as a pulp capping, 
for nearly all the cases which had been so treated were found to be in a 
devitalized and mummified condition. 

As an obtundent of hypersensitive dentin in shallow cavities it is of 
great value ; but its application to deep-seated caries, or where the pulp is 
almost exposed, its use is to be deprecated for the reasons given above. 

Zinc oxyphosphate cement is employed by some operators to the exclusion 
of all other materials for capping the pulp in this class of cases. To pre- 
vent the irritation and pain which would follow its direct application to 
the dentin various substances are used to line the cavity, — viz., solutions 
of chlora-percha, varnishes, Canada balsam, and zinc sulphate. 

As a further protection against thermal shock the bottom of the cavity 
may be covered with a disk of sheet asbestos, blotting-paper, writing-paper, 
horn, quill, cork, vulcanite, or ivory, which may be secured in place with 
chlora-percha, copal varnish, or Canada balsam, and zinc oxy phosphate 
flowed over it. 

Incomplete Exposures due to Caries. — Incomplete exposure of the 
pulp may be described as that condition in which a single cornu or horn 
of the pulp is exposed as the result of caries or from traumatic injury. 
This class of exposures occurring as the result of caries, the exposure of 
recent origin, and in which the irritation and pain have not been mani- 
fested for more than twenty-four hours, are many times amenable to con- 
servative treatment. 

Exposures of this class, if caused by traumatic injury during the ex- 
cavation of the cavity, give better prospects of successful conservation 
than those produced by caries, for the reason that the latter are generally 
more or less infected with the pyogenic micro-organisms ; while in the 
traumatic cases, if treated upon surgical principles, infection can be pre- 
vented and the pulp maintained in a normal condition by the exclusion of 
the micro-organisms and other sources of irritation and protecting it from 
pressure. 

Symptoms. — Incomplete exposure of the pulp, due to caries, some- 
times presents a history of intervals of irritation and pain, more or less 
severe, covering a period of a few hours or days. Finally the patient is 
robbed of a night's sleep by the severity of the pain, and next morning 
seeks j>rofessional advice. The pain is described as sharp, stinging, or 
burning in character, and the affected tooth is exceedingly sensitive to 
heat and cold, sweets and acids, or pressure of food within the cavity. 
Paroxysms of pain are induced by contact with any of these irritating sub- 
stances, while it is aggravated by vigorous exercise, by lowering the head, 
as in stooping to pick something from the floor, or by assuming the hori- 
zontal position. Exercise and the positions mentioned increase arterial 
tension in the head, and thus by the increased pressure of blood in the 
pulp, pain is induced or augmented. The pain in the early stages of irrita- 
tion is never very severe, but as the case progresses towards inflammation 



420 OPERATIVE DENTISTRY. 

it becomes more and more intense, with shorter intervals of respite, until 
finally the pain becomes of a sharp, deep-seated, throbbing character and 
well-nigh continuous, which denotes a high degree of congestion. These 
symptoms are doubtless due, in a majority of instances, to septic infection 
from the pyogenic. bacteria found in the oral secretions and food debris 
lodged in the mouth and between the teeth. With proper treatment fol- 
lowing antiseptic lines even a case of this character is not entirely beyond 
hope of successful conservation, provided, as already mentioned, these 
symptoms have not been manifest more than twenty-four hours. 

Treatment. — The treatment consists, first, of efforts to allay the pain 
by removing the causes of irritation and subduing the hypersemia, and 
secondly, of protecting the pulp against the further influence of these exciting 
causes of incipient inflammation. 

The cavity should first be carefully syringed with tepid water to 
which has been added a little soda bicarbonate and an antiseptic like 
listerine, pasteurine, or borolyptol, to remove the food debris, neutralize 
the acid condition, and correct to a certain degree the septic condition. 
Many times this procedure will relieve the severity of the pain in a few 
minutes, or entirely control it. The rubber dam should then be adjusted, 
the cavity carefully dried with bibulous paper or amadou, and the carious 
matter deftly removed, care being exercised not to wound the pulp, as such 
wound would endanger the vitality of the pulp by furnishing an open gate- 
way for the entrance of the pyogenic bacteria to its deeper structures. 

If the pulp is accidentally wounded, the bleeding point should be 
touched with oil of cloves or other efficient but non-escharotic antiseptic. 
The walls of the cavity may now be saturated with oil of cloves, oil of 
cassia, or the volatile extract of eucalyptus, and the exposed cornu of the 
pulp protected with a metal cap or other suitable rigid covering, the con- 
cavity of which has been filled with a paste composed of oil of cloves and 
zinc oxide, or zinc oxysulphate cement. The object of the paste or the 
cement is twofold, — first, to furnish an antiseptic dressing for the exposed 
crown of the pulp, and secondly, to seal the perforation of the pulp-chamber 
with a non-irritating substance, which would effectually prevent any pro- 
trusion of the pulp beyond its normal limits. 

Over the cap should now be flowed a thick solution of chlora-percha 
or zinc oxysulphate, and after this has set the cavity may be filled with 
gutta-percha stopping or zinc oxyphosphate. 

Prognosis. — The prognosis in these cases will depend upon the local 
condition of the pulp when capped, the surgical care with which the 
cavity has been prepared and sterilized, the dexterity with which the 
antiseptic dressing has been applied, the methods used to prevent pressure 
upon the exposed portion of the pulp, the protection afforded against 
thermal shock by the overlying filling-material, and the constitutional 
condition of the patient at the time of the operation and for some months 
thereafter. 

If the inflammatory symptoms have not passed beyond the stage of 
hyperemia — and this may be known by the character and duration of the 
pain as already indicated — and the surgical and antiseptic technique has 



EXPOSURE OP THE DENTAL PULP AND ITS TREATMENT. 421 

been carefully carried out, the prognosis will be fairly favorable, provided 
the health of the patient is good at the time of the operation and so con- 
tinues. Anaemic conditions, plethora, pregnancy, nervous debility, tuber- 
culosis, and syphilis are contraindications for the conservative treatment 
of the pulp. 

It must be remembered, however, that whatever form of capping is 
employed to conserve the vitality of the pulp, its ultimate success as an 
operation depends upon the formation of secondary dentin at the point 
of injury which shall remove the dangers of the devitalization of the pulp 
caused by the disease or the injury, and this cannot be assured until after 
the lapse of a considerable period of time, usually from one to two or 
three years. 

Although it is true that a large proportion of these cases will do well 
under favorable circumstances, yet it is equally true that at the end of this 
time a certain number will be found to have lost their vitality, even though 
little discomfort or none at all had been experienced. 

Incomplete Exposures of the Pulp due to Traumatism. — Trau- 
matic incomplete exposures of the pulp are usually the result of accidents 
during the excavation of a carious cavity, or from mechanic abrasions or 
chemic erosions, but occasionally it may occur from an external injury 
which fractures a portion of the crown and leaves one of the cornua 
exposed. 

In traumatic exposures of the pulp due to accidents in excavating, the 
cornu of the pulp is usually wounded, and is followed by hemorrhage and 
acute pain, which, however, soon subsides. The bleeding point may be 
treated as just described, or irrigated with a five per cent, warm solution 
of carbolic acid,— escharotics should be avoided, — and as soon as hemor- 
rhage has ceased the extent of the injury can be ascertained, when, if it does 
not extend beyond the involvement of the cornu of the pulp or a very 
small opening into the chamber, the excavation may be completed and the 
case treated by capping upon the lines already indicated. If, however, the 
pulp has been seriously wounded by the instrument slipping into the bul- 
bous portion and causing a complete exposure, devitalization is the only 
remedy. 

In exposures due to abrasions, erosions, and external traumatisms which 
fracture the crown, conservative treatment is out of the question, as 
there is no means of adequately protecting the pulp against the irritating 
influences which surround it. Devitalization or immediate extirpation 
must therefore be resorted to in order to relieve the patient of the suffer- 
ing incident to an exposure of this character. 

SECONDARY DENTIN, OR DENTIN OF REPAIR. 

One of the main objects sought in the conservative treatment of the 
exposed pulp is to stimulate nature to repair the breach made in the walls 
of the pulp-chamber by disease or traumatism, or to protect the pulp 
against a threatened breach of its walls by the interposition of a new- 
formed tissue laid down by the odontoblasts. In the study of the forma- 
tion and calcification of the dentin (Chapter II.) it has been shown that t he 



422 OPERATIVE DENTISTRY. 

chief function of the odontoblasts, which are arranged in a continuous 
layer over the entire periphery of the pulp, was that of forming or build- 
ing the dentin, and that upon the completion of the formative process the 
function ceased. 

The function, however, of the formative cells is not lost, for it fre- 
quently happens that under the stimulation of irritation occurring at any 
period of life, produced by mechanic abrasion, chemic erosion, caries, and 
other forms of external irritation, the odontoblasts again become active 
and deposit calcific material within the dentinal tubuli, termed tubular 
calcification, or lay down at the point of irritation a peculiar calcific mate- 
rial, termed secondary dentin, the dentin of repair of Salter, in a seeming 
effort to build a barrier against the encroachment of the disease or injury 
upon the territory of the pulp (Fig. 510). These deposits are always found 
opposite, or rather at the base of, the dentinal fibrillar involved in the 
irritation. Calcific material is also laid down by the odontoblasts in tem- 
porary teeth retained beyond their normal period, and as a senile condition 
in the teeth of elderly people (Fig. 511), the pulp-chamber and canal being 
sometimes almost obliterated by this process. 

Secondary dentin has sometimes a very close resemblance to normal 
dentin, but it is by no means a perfect example of this structure. In the 
new formation as found in persistent temporary teeth, in the senile calcifi- 
cation of elderly persons, and in cases of chronic irritation, the new-formed 
tissue often approaches the perfection in structure of normal dentin, while 
in those cases which are dependent upon some form of external irritation 
like mechanic abrasion, chemic erosion, or caries, the new-formed tissue 
which has been developed to shield the pulp against these irritating influ- 
ences often presents a low grade of structural organization, the tubules 
being scanty, very irregular in their course, and the tissues more dense 
than normal dentin, while occasionally it will be almost structureless. 

Dr. Black * is of the opinion that the formation of secondary deposits 
within the pulp-chamber, in cases of exposed pulps which have been 
capped, do not permanently conserve the vitality or the health of the pulp, 
but that they usually produce exhaustion, degeneration, and finally death 
of the organ. 

He looks upon those cases of capping as the most hopeful which have 
passed on for years without the formation of any deposit whatever, very 
many of which seem to remain indefinitely in a perfectly healthy con- 
dition. 

Dr. Truman f says new formations are usually expected from capping 
pulps 5 but this expectation is rarely realized, as here the irritation is 
excessive and becomes a destructive force. 

Complete exposure of the pulp is that condition in which the inva- 
sion of caries has penetrated the pulp -chamber and laid bare, to a greater 
or less extent, the body or bulbous portion of the pulp, or a traumatic 
injury has caused the loss of a sufficient amount of the crown to open the 
pulp- chamber and expose its vital contents. Complete exposures of the 

* American System of Dentistry. f Ibid. 




Secondary del 




Fig. 510. — Vertical section of human cuspid, sho 
portion of the pulp-chamber as a result i 



A 



>f secondary dentin in the coronal 
t the morsal edge. ■; 100. 




Secondary dentin 



Fig. 511.— Vertical section of human central incisor, showing formation of secondary dentin m the 
coronal portion of the pulp-chamber. ;< 10-. 



EXPOSUEE OF THE DENTAL PULP AND ITS TREATMENT. 423 

pulp, due to caries, are rarely amenable to conservative treatment by 
reason of the inflammatory symptoms which are always present. These 
symptoms may be acute or chronic in their character. When the symptoms 
are acute and the opening into the pulp-chariiber is small, so that the pulp 
is confined within the pulp-chamber, the swelling which takes place causes 
pressure upon the blood-vessels, which results in stasis, general infarction, 
and death, — gangrene of the organ. If, on the other hand, the opening 
into the pulp-chamber is large, so that the pulp in swelling finds relief 
from the pressure by a portion of its congested tissue escaping through 
the opening into the cavity of decay, stasis and infarction are sometimes 
avoided, and the inflammatory symptoms assume a low form or chronic 
type. In either case devitalization of the pulp is the only satisfactory 
method to pursue, as efforts to conserve its vitality usually prove futile. 
Traumatic exposures of a like character are likewise not amenable to con- 
servative treatment, and in all such cases the pulp should be extirpated 
by the immediate method under local or general anaesthesia. 

DEVITALIZATION AND EXTIRPATION OF THE PULP. 

Three general methods are employed for the devitalization and extirpa- 
tion of the dental pulp : first, by the cliemic action of drugs ; second, by 
instrumentation / and third, by local or general anaesthesia. 

The drugs which have been used for devitalizing the pulp by means of 
their chemic action are arsenous acid, zinc chloride, cobalt (arsenical ore), 
caustic potassa, and chromic acid. 

The requirements of a devitalizing agent are, — 

1. That it act painlessly. 

2. That it destroy vitality promptly. 

3. That the action of the drug shall not produce discoloration of the 
dentin. 

Devitalization of the pulp is generally accomplished by the application 
of arsenous acid (arsenic trioxide), which destroys the vitality of the organ 
en masse. No other remedy used for this purpose possesses the above 
requirements in so large a degree, or is so prompt, certain, and complete 
in its devitalizing effect upon the dental pulp ; and yet, as the result of 
accident or in careless hands, it is capable of doing great damage to the 
surrounding tissues, and on this account some operators who have wit- 
nessed its destructive effects upon the gingival tissues and the alveolar 
processes have discarded its use altogether. It still, however, remains the 
u sheet-anchor " of the profession for this purpose despite the ill effects 
which sometimes follow its use. 

Arsenic trioxide was first introduced for the purpose of devitalizing 
the dental pulp by Spooner (1836), and when employed with proper care 
there is no remedy which gives such universally good results. Arsenic 
trioxide is usually combined with acetate of morphine in various propor- 
tions, and creosote, carbolic acid, and oil of cloves, or other essential oil, 
added to form a creamy paste. 

The earliest combination of this character was the formula of Dr. J. 
D. White (1855) : 



424 OPEEATIVE DENTISTRY. 

R Arsenous acid, 

Morphise sulph., aa gr. x to xv ; 
Carbolic acid, q. s. ft. paste. 

A later formula is that of Dr. J. Foster Flagg (1877) : 

R Arsenous acid, gr. v ; 
Morphine acetas, gr. x ; 
01. caryophylli, q. s. ft. paste. 

A more recent combination substitutes cocaine hydroclorate for the 
morphine : 

R Arsenous acid, gr. x ; 

Cocainje hydrochl., gr. xx ; 
01. cinnanionri, q. s. ft. 



Miller (1894) recommended the following formula as possessing advan- 
tages over those containing morphine, as the thymol which is substituted 
for the morphine exceeds it in its local anaesthetic action, and has the 
decided advantage of possessing a considerable antiseptic quality : 

R Thymol, 

Arsenous acid, aa gr. x ; 

01. caryophylli, q. s. ft. paste. 

Morphine. — The object in adding this drug to the paste is to utilize 
its narcotic properties to relieve the severity of the pain, which is often 
induced by the irritating effect of the arsenic upon the tissues of the pulp. 

Carbolic acid (deliquesced crystals) is a notable escharotic, while it also 
possesses antiseptic and local anaesthetic or analgesic properties, which 
make it a valuable ingredient of a devitalizing paste. Carbolic acid alone 
is capable of devitalizing the pulp. 

Creosote is not so vigorous an escharotic as carbolic acid, while it pos- 
sesses about the same degree of antiseptic and local anaesthetic power. 

Oil of cloves is but very slightly escharotic, while its antiseptic and 
local obtunding effect is very considerable. 

Cocaine hydrochl orate is substituted for the morphine because it possesses 
such strong local anaesthetic powers. 

Oil of cinnamon is added for its antiseptic qualities. 

Thymol is used for its local anaesthetic and antiseptic action. 

Chloretone is also used for its local anaesthetic effects, and is preferred by 
some operators to cocaine, as it is non -poisonous. (See chapter on anaes- 
thesia. ) 

PHYSICAL EFFECTS OF AESENIC UPON THE PULP. 

The application of arsenic trioxide to the living pulp produces certain 
definite phenomena which are irritative in their character, and represent 
the earlier physical phenomena of acute inflammation, — viz., arterial 
hyperaemia, pain, increasing from a low grumbling, gnawing character to 
acute, violent paroxysms, followed by acute congestion of the blood-ves- 
sels, exudation, and finally apical strangulation, or general infarction, 



EXPOSURE OF THE DENTAL PULP AND ITS TREATMENT. 



425 



which effectually prevents egress or ingress of the blood-stream, causing 
complete stasis and death of the organ. Fig. 512 is made from a section of 
a pulp which had been treated with arsenic, and shows the congestion and 
enlargement of the blood-vessels. 




Section of dental pulp. Blood 



Flagg* describes the phenomena as follows : "A minute portion of the 
arsenic being introduced into the circulation of the pulp acts as a dy- 
namic, vital irritant, which causes, first, a determination of blood to the 
organ, resulting, in from fifteen to twenty minutes, in uneasiness and throb- 
bing pain ; secondly, congestion, which causes a cessation of the throbbing 
character of the pain '; thirdly, usually, complete cessation of pain, leaving 
like the going down of a wave ; this condition has a varied length of dura- 
tion, dependent upon the extent and frequency of the previous pulp irri- 
tation, extent of pulp exposure, temperamental impressibility, — nervous 
irritability, — systemic ability to resist and react, — vital resistance, — and such 
like considerations. The death of the pulp en masse being due to strangu- 
lation of the vessels at the apex in consequence of the congestion." 

Animal tissue when thoroughly impregnated with arsenic trioxide, even 
in small amount, is rendered proof against putrefaction, but dental pulps 
which have been devitalized by this drug are only very exceptionally ren- 
dered proof against the putrefactive process. Arsenic in large quantity, 
locally applied, is an energetic and powerful escharotic or caustic, but its 
action is somewhat slow as compared with carbolic acid, zinc chloride, 
caustic potassa, and chromic acid. Its escharotic effect is more marked and 
rapid upon tissues of low vitality — abnormal growths — than upon normal 
tissue. Absorption, however, takes place much more rapidly in healthy 



J. Foster Flagg, Dental Cosmos, July, 1877. 



426 OPERATIVE DENTISTRY. 

than in highly inflamed or dead tissue. This fact explains why, in com- 
paratively healthy pulps, devitalization with arsenic is so much more rapid 
and effective than in those which are inflamed, partially calcified, or other- 
wise diseased. In the former a single application is usually all that is 
necessary to effect complete devitalization, while in the latter two, three, 
and even four applications are sometimes required. 

Arsenic when used in large quantities upon an extensive surface, as in 
the treatment of cancer of the breast and lupus in which the application has 
been intentionally permitted to include surrounding healthy tissue, absorp- 
tion of the drug by the healthy tissue may take place — before its devital- 
izing action renders the tissue incapable of conveying it to the circula- 
tion — in such quantities as to produce constitutional effects or endanger 
life. That such a condition could be possible as a result of pulp-devital- 
ization seems beyond the possibilities of peradventure, while, upon the 
other hand, irritation of the apical space or the tissues beyond, resulting 
from the application of an arsenical dressing to a vital pulp in other than 
deciduous teeth, and in the permanent teeth of young children before the 
completion of calcification of the roots in which the foramina are very 
large, could only occur, if intelligently used, as a rare and accidental 
circumstance. 

The violent irritating action of arsenic when coming in contact with 
the surface of the pulp immediately causes arterial hypersemia, while the 
devitalizing effect produced upon the tissue lying in immediate contact 
with it renders the devitalized tissue incapable of absorbing the drug, 
and thus prevents it being carried into the circulation except in an 
infinitesimal quantity, too small to provoke irritative inflammation at the 
apical space. 

Flagg,* in experiments instituted by him to ascertain the amount of 
arsenic absorbed by the pulp, found it ' ' almost incomprehensively minute, 
never more than one millionth (?) of a grain." He further maintains that 
the apical irritation which often follows upon the fourth to the seventh 
day after arsenical devitalization is not due to the effects of arsenic which 
has passed to the apical foramen, but to inflammatory conditions extend- 
ing to the apical portion of the pulp, and are the last stages of the process 
of devitalization, as may be readily shown by microscopic examination 
of the apical extremity of a pulp removed at this time, and which is 
further proved by the subsidence of the pericemental symptoms in a few 
hours, or at most in twenty-four to forty-eight hours. 

Arkovy presented an elaborate study of the action of arsenic upon the 
dental pulp at the International Medical Congress, 1881, which may be 
briefly summarized as follows : arsenic trioxide (As. 2 3 ) when applied 
to a vital dental pulp induces : 

"1. Hyperemia, partial or complete, depending upon the amount of 
the drug used ; expansion of the blood-vessels, with a tendency to throm- 
bosis and capillary embolism. 

" 2. It does not produce coagulation of the tissue. 

* Dental Cosmos, July, 1877. 



EXPOSURE OF THE DENTAL PULP AND ITS TREATMENT. 427 

"3. It seems to possess a specific influence upon the blood-corpuscles, 
combining with the haemoglobin to form a compound of arsen-hsemoglobin. 
which produces a yellowish tinge of the pulp-tissue and affects the color 
of the blood. 

"4. The drug is conveyed in substantia into the blood-channels, where 
it produces, besides the changes already mentioned, disintegration of their 
contents — granular detritus — and shrinkage or anaemic collapse of the ves- 
sel walls. This being most noticeable where large doses had been used. 

"5. The connective-tissue fibres and the odontoblasts undergo no 
change, but the connective-tissue cells are increased from three to four 
times their normal size. 

"6. The effects upon the neurilemma is to somewhat increase the num- 
ber of its nuclei, while in the axial part granular destruction of the myelin 
sets in and the axis-cylinder begins in various locations to disappear ; 
while in others the notchy tumefaction of the axis- cylinder, usually seen 
only in cases of central lesion, can be plainly made out. 

u l. These alterations are found scattered throughout normal-looking 
tissue. 

"8. The pulp, in whole or in part, and the neighboring dentin and 
cementum, are tinged a brownish red when large doses of the drug are em- 
ployed. This discoloration is most marked in the pulp at the top of the 
bulbous portion and at the apical fourth or third." 

Miller in experimenting upon the tails of mice found that "the action 
of the arsenic appeared to be somewhat accelerated when a glass ring was 
applied close to the root of the tail. This was done to simulate the sur- 
roundings of the apical vessels. In more than forty cases there was not 
one in which the action of the arsenic extended beyond the ring, and the 
action was not appreciably affected by enclosing the tails in plaster casts. 
The action of the arsenic is of a progressive nature, beginning at the point 
of application and extending gradually in each direction." 

Miller denies that arsenic trioxide produces escharotic effects upon the 
pulp like that of zinc chloride or carbolic acid, etc., and states, "The 
local application produces no immediate visible effect whatever." 

Method of Application. — In the application of arsenic for the de- 
struction of the vital pulp certain important considerations are presented. 

1. Dosage. — The amount of the drug that may be safely applied is 
from one-sixteenth of a grain (0.001 gramme), or from that to one-thirtieth 
of a grain (0.002 gramme). The writer has found, however, in his expe- 
rience, that one-hundredth of a grain (0.0006 gramme) was just as 
effective as a larger amount, provided it was permitted to remain in con- 
tact with the pulp for from three days to one week. The larger the dose 
the quicker the death, and vice versa, but the large dose is usually very 
painful, while the small dose will devitalize with absolutely no pain at all. 

The one-hundredth part of a grain is an exceedingly small quan- 
tity, and yet it can be approximated as readily as the one-sixteenth of a 
grain after the actual amount has once been weighed out and observed. 
The approximate amount is all that is aimed at, for no one would think it 
necessary to weigh out each dose to be applied. 



428 OPERATIVE DENTISTRY. 

For many years the writer has not used morphine, cocaine, or other 
obtunding drug, except carbolic acid, in combination with arsenic for de- 
vitalizing the pulp, and has found it exceedingly rare that pain has been 
produced by the application, or that he has failed to painlessly remove the 
pulp at the end of a week or ten days. The exceptions have been cases 
in which severe irritation and hyperaeinia were present before the applica- 
tion was made. The text-books usually warn the student not to nse any 
coagulating drug in combination with arsenic, as the coagulum prevents the 
arsenic from taking effect. Clinical experience upon the part of the writer 
does not substantiate this teaching. 

2. Placing the Dressing. — The cavity should first be syringed with 
tepid water containing an antiseptic or an alkali like soda bicarbonate. 
Next the rubber dam should be adjusted, — and this is wise in all cases 
before making an application of arsenic, — the cavity carefully dried, and 
the dressing, which should be composed of a piece of cotton the size of a 
pin-head, may be moistened with ninety-five per cent, carbolic acid, and 
the dry arsenic, which has been previously measured out, gathered up 
with the moistened dressing and then laid carefully over the point of ex- 
posure. 

A somewhat larger dose is necessary in cases of pseudo-exposure, as 
the drug is slow in penetrating the dentin even though completely decal- 
cified. 

3. Sealing the Cavity. — It has been customary to seal the cavity con- 
taining an arsenical dressing with cotton and sandarach or with tempo- 
rary stopping. Neither of these materials are really suitable for the pur- 
pose, as the first soon gets foul and very offensive, while from swelling 
of the cotton fibre or compression from the force of mastication painful 
pressure upon the pulp is induced. The temporary stopping is also liable, 
especially in crown cavities, to be compressed by mastication and produce 
painful pressure upon the pulp ; while both of them are open to the seri- 
ous objection of forming leaky stoppings, which, if employed in approxi- 
mal, labial, or buccal cavities extending beneath the gum, might lead to the 
escape of a portion of the arsenic and destruction of the soft tissues and 
alveolar process immediately surrounding the tooth. Zinc oxyphosphate 
mixed to a creamy paste and introduced so as to avoid pressure is the only 
safe material with which to seal a cavity containing an arsenical dressing. 
If this material were universally used for this purpose, sloughing of the 
gum, necrosis of the alveolus, and loss of the tooth, as a result of the 
escape of the arsenic, would become, except in rare cases due to accidental 
causes, a bygone experience. 

In those cases which give evidence, by pain, of considerable hypersemia, 
palliative treatment should first be employed to relieve the suffering and 
reduce the congested state of the pulp-vessels, as by this means devitaliza- 
tion may be rendered more sure and at the same time nearly if not quite 
painless. The cavity should first be disinfected with a tepid carbolic acid 
solution — two per cent. — or a solution of formol, two to five per cent. 

Formol is composed of forty volumes of formaldehyde and sixty of 
water. The former per cent, is made by adding one volume of formol to 



EXPOSURE OF THE DENTAL PULP AND ITS TREATMENT. 429 

nineteen volumes of water, the latter by adding one volume of formol to 
seven volumes of water. 

Formol owes its value as a disinfectant to its great diffusibility in the 
strengths above mentioned ; it, however, possesses coagulating power. 

The application of formol to an exposed pulp is at first slightly painful, 
but this immediately passes away and the effect is eminently soothing. 

The pulp may now be dressed with morphine and one of the essential 
oils, and the cavity sealed for several days with temporary stopping or zinc 
oxyphosphate ; the latter being preferable from the fact that pressure is 
avoided and the pulp given complete protection against all external irri- 
tating agencies. 

Some operators prefer to dress the pulp with cocaine hydrochlorate and 
oil of cinnamon. 

Pulps which have been exposed for some time usually show evidences 
of suppuration. These cases should be treated by first removing as much 
as possible of the decalcified dentin around the exposure as can be done 
without producing much pain, and carefully syringing the cavity to remove 
the debris and wash away the pus. The arsenical dressing should be placed 
in direct contact with the pulp and sealed in by the method above described. 

After the arsenical dressing has been removed, it is well to follow 
this treatment with a dressing of tannic acid for a few days, as the tannin 
hardens the pulp and facilitates its removal. 

Dr. Harlan has recommended swabbing the cavity with the sesquioxide 
of iron, as this unites with the arsenic, forming an insoluble compound, 
and thus prevents any further action of this agent. Sesquioxide of iron 
(ferric hydrate, Fe 2 (HO) 6 ) is made by precipitating ferric sulphate or ferric 
chloride by adding ammonia or sodium hydrate. The precipitate should 
be allowed to drain on muslin for a few minutes. The soft mass or magma 
should be placed in the cavity of the tooth. In local poisoning from 
arsenic the magma should also be placed over the inflamed gum as well as 
in the cavity of the tooth. 

Occasionally a small fragment of living pulp will be left in the apical 
portion of the canal, which is still very sensitive. It is better to destroy 
this by repeated applications of ninety-five per cent, carbolic acid than to 
reapply arsenic, for fear of it going beyond the apical foramen. Danger 
also exists of mistaking an enlarged apical foramen for a piece of vital 
pulp remaining in the canal. 

Errors of this character have been made by some of the very best and most 
careful practitioners. In all such cases it is better to err upon the safe side 
rather than to cause the loss of a tooth by a careless or mistaken diagnosis. 

Discoloration of the Dentin. — This condition often follows a violent 
congestion of the pulp, which has been caused by external irritants. The 
discoloration is produced by the disorganization of the blood-corpuscles and 
the distribution of the haemoglobin through the dentinal tubuli. Arsenic 
applied in large quantity for the devitalization of the pulp usually pro- 
duces a violent congestion, and more often results in producing discolora- 
tion of the dentin than when the drug is used in small quantities. 

It is therefore important in all cases of highly congested pulps to 



430 



OPERATIVE DEK T I STRY . 



relieve this condition by palliative treatment or local depletion before 
applying the arsenic. 

Devitalization of the pulp with arsenic will rarely result in this un- 
fortunate condition if the above precautions are taken and the amount of 
arsenic used does not much exceed one-hundredth part of a grain. 

Extirpation of the Pulp. — The devitalized pulp should be removed at 
the end of a week or ten days after the application of the arsenical dressing, 
for the reason that at this time it can be done without pain or hemorrhage, 
as the natural process of separation or exfoliation has taken place between 
the dead and the living tissues at the apex of the root. If it is allowed to 
remain much beyond this period, pericemental irritation is likely to follow 
as a result of putrefactive decomposition and local septic poisoning. 

The removal of the dead pulp-tissue may be accomplished by first 
thoroughly opening the pulp-chamber with burs or excavators upon lines 
which will give the most direct access, and 
then passing a fine barbed broach (Fig. 513) 
to the apex of the canal, rotating it once or 
twice in the same direction, and upon with- 
drawing it the pulp will be found entangled 
upon the barbs of the broach. If, however, 
the tissue of the pulp has been softened by 
decomposition and does not come away with 
the instrument, it must be broken up and 
removed by constant rotation of the broach, 
or fibres of cotton may be wrapped upon a 
plain Swiss jeweller's broach and rotated in 
the canal. This is the very best method of 
removing the remains of a pulp which has 
become liquefied by decomposition. 

The writer has sometimes adopted a method that was advo- 
cated in the journals several years ago (1872 or 1874) for 
removing pulp debris which could not be extracted with the 
broach, — viz., the introduction into the pulp-cavity and canals 
of pure pepsin dissolved in water acidulated with hydrochloric 
acid, 1 to 250, and carried into them by the means of fibres of 
cotton which had been saturated in the solution. This was 
sealed into the tooth with gutta-percha or zinc oxyj>hosphate 
and allowed to remain for twenty-four hours. The object of 
this method was to digest the remnants of the pulp and render 
them fluid, so that they could be washed out by irrigation or 
removed by absorbent cotton wound upon a broach. The result 
of such treatment is not only the removal of the pulp debris, 
but it also sweetens the canals and completely removes the odor 
of decomposition. 

If the pulp is extirpated at the end of a week or ten days B %roaches Ve ~ 
after devitalization it will come away entire to the very apex 
of each canal, leaving these channels clean and in a fit condition to be 
immediately filled. 







CHAPTER XXVI. 

PULPLESS TEETH AND FILLING PULP-CANALS. 

Definition. — A tooth, which contains a devitalized pulp is said to be 
dead ; a better term to designate this condition is pulpless, for the reason 
that the tooth cannot be correctly designated as dead so long as it main- 
tains a vital connection through its pericementum with the alveolus of the 
jaw ; but when this membrane has lost its vitality or has been destroyed, 
the tooth may then be correctly termed dead or necrosed, for it has no 
further vital connection with the economy. 

All devitalized or pulpless teeth may be classed, from the surgical 
stand-point, under two heads, — viz., aseptic and septic. Inasmuch as the 
septic cases are the most common they will be considered first. 

Septic pulp-canals are those which are invaded by the pyogenic and 
saprophytic micro-organisms, and contain decomposing or putrefying tissue 
in greater or less quantity, food debris, the fluids of the mouth, or other 
material which forms a suitable soil for the growth and propagation of this 
class of organisms. (See Chapter V.) 

Devitalization of the pulp is usually the result of caries and exposure 
of this organ, followed by septic infection, inflammation, and suppuration ; 
consequently the great majority of the cases of pulpless teeth which are 
presented for treatment are in a septic condition. Another class of septic 
cases are those in which the pulp of a perfectly sound tooth has lost its 
vitality from some traumatic injury or from embolism, but which perhaps 
for months or years thereafter has given no evidence of its condition 
except by the change in the color of the tooth. Suddenly,, however, symp- 
toms of a septic inflammation of the pericemental membrane become un- 
mistakably manifest ; and as there is no external communication with the 
devitalized pulp through a carious cavity by which the infection could 
have entered from the outside, it is fair to presume that the organisms 
which have established the suppurative process found a lodgement at the 
apical space, having been brought there through the avenues of the circu- 
lation. On the other hand, teeth of this class, when opened for the purpose 
of removing the dead and mummified pulp, often take on the most violent 
septic inflammation as the result of the admission of pathogenic organisms 
from the atmosphere or the fluids of the mouth. In all such cases the 
greatest care should be taken to prevent septic inflammation by the use of 
the rubber dam, and keeping the cavity through which the pulp-chamber 
is to be reached flooded with a strong antiseptic, like carbolic acid (ninety- 
five per cent.) or a sublimate solution (1 to 1000 or 1 to 500), so that when 
the pulp- chamber is opened an antiseptic of sufficient strength will be 
carried into it to prevent the growth and propagations of the micro- 
organisms. Devitalized pulps which have not been infected either from 
external sources or through the avenues of the circulation dry up and 
become mummified. 

431 



432 OPERATIVE DENTISTRY. 

The sequelae of septic infection of devitalized pulps are pericementitis, 
dento-alveolar abscess, septicemia, and pyaemia. 

Pulpless teeth which present septic canals are rarely ever entirely free 
from a certain amount of pericemental irritation, which is due to the toxic 
effect of the ptomaines developed from the action of the micro-organisms 
upon the gangrenous pulp, and which has been forced into the apical space 
by the pressure of gases, gravity, or by instrumentation. 

If the organisms which have attacked the gangrenous pulp are of viru- 
lent type, active inflammation of the pericementum and alveolar abscess 
are likely to follow. The severity of the inflammatory symptoms is gov- 
erned in part by the character of the infecting organisms, and in part by 
the local resistance of the tissues and the diathesis of the individual. In 
those persons affected with tuberculosis and syphilis, either inherited or 
acquired, or who are suffering from general debility, diabetes, or albu- 
minuria, inflammation is prone to run a rapid and severe course. 

Aseptic pulp canals are those in which for various reasons, like persist- 
ent hyperemia due to caries, abrasion, or fracture, but which has not 
exposed the pulp, or for the purposes of grafting a crown or setting a 
bridge, devitalization of the pulp by the application of arsenous acid has 
become a necessity. The removal, under antiseptic precautions, of such 
pulps as soon as separation or sloughing has taken place at the apex 
leaves the canals in an aseptic condition, and no other treatment is re- 
quired than that of filling the canals at the same sitting and before the 
rubber dam is removed. The septic cases, however, often require several 
treatments before they are in a suitable condition to warrant the filling of 
the canals ; in fact, this should never be done while there is any mephitic 
odor emitted from the canals, or there is any pericemental soreness, as 
these are unmistakable evidences that septic conditions still prevail. Im- 
mediate root-filling of crooked septic canals is to be most strongly depre- 
cated, as the inevitable result is an alveolar abscess. 

If, however, the canals can be rendered aseptic by a single treatment, 
— and this is possible in some cases, as, for instance, in the anterior teeth 
when the canals are straight and of large size, — immediate filling of the 
root is the only correct practice. Many practitioners make the mistake of 
over-treating such cases, thus keeping up an irritation which might be 
avoided by sterilization and immediate filling of the root-canal. 

Preparation and Treatment of Pulp-Canals. — In the treatment of 
septic pulp-canals the object aimed at is that of so changing the condi- 
tions as to render them aseptic. This is accomplished by first excluding 
the secretions of the mouth by applying the rubber dam and maintaining 
absolute dryness of the field of operation in all subsequent treatments. 
When the treatment has once been commenced, from that time onward 
to the completion of the final operation the secretions of the mouth 
should never be allowed to again contaminate the pulp-canals. Fail- 
ure to observe this rule often renders the treatment of the case tedious 
and unsatisfactory. The application of the rubber dam as the first step 
in all the subsequent treatments is the only way to insure positive aseptic 
conditions. 






Fig. 514.— Superior left cen- 
tral incisor. Labio-lingual 
longitudinal section, showing 
pulp-canal. 



Fig. 515.— Superior right cen- 
tral incisor. Mesio-distal longi- 
tudinal section, showing root- 
canal. 



Fig. 516.— Superior left lat- 
eral incisor. Labio-lingual 
longitudinal section, showing 
root-canal. 






Fig. 517.— Superior left lat- 
eral incisor. Mesio-distal longi- 
tudinal section, showing root- 
canal. 



Fig. 518.— Inferior left cen- 
tral incisor. Labio-lingual 
longitudinal section, showing 
root-canal. 



Fig. 519. — Inferior right cen- 
tral incisor. Mesio-distal longi- 
tudinal section, showing root- 
canal. 






Fig. 520.— Inferior left lat- 
eral incisor Labio-lingual 
longitudinal section, showing 
root-canal. 



Fig. 521.— Inferior right lat- 
eral incisor. Mesio-distal longi- 
tudinal section, showing root- 
canal. 



Fig. 522.— Superior right cus- 
pid. Labio-lingual longitudi- 
nal section, showing root- 
canal. 






Fig. 523.— Superior left cus- 
pid. Mesio-distal longitudinal 
section, showing root-canal. 



Fig. 524.— Inferior left cuspid. 
Labio-lingual longitudinal sec- 
tion, showing root-canal. 



Fig. 525.— Inferior right cus- 
pid. Mesio-distal longitudinal 
section, showing root-canal. 




Fig. 526.— Peculiarities in inferior cuspids and bicuspids. A, bifurcated inferior cuspid ; B, bifurcated 
canal, inferior first bicuspid ; C, bifurcated canal (middle third), inferior second bicuspid. 







D 




Fig. 527.— Superior right first 
bicuspid. Bucco-lingual longi- 
tudinal section, showing bifur- 
cation of root and canals. 



Fig. 528.— Superior left first 
bicuspid. Base of pulp-cham- 
ber, showing entrance to root- 
canal. 



Fig. 529. — Superior right sec- 
ond bicuspid. Bucco-lingual 
longitudinal section, showing 
root-canal. 



D 




Fig. 530.— Superior right sec- 
ond bicuspid. Base of pulp- 
chamber, showing entrance to 
root-canal. 



Fig. 531.— Inferior right first 
bicuspid. Bucco-lingual longi- 
tudinal section, showing root- 
canal. 



Q 




D 



Fig. 532.— Inferior left first 
bicuspid. Base of pulp-cham- 
ber, showing entrance to root- 
canals. 



Fig. 533.— Inferior right sec- 
ond bicuspid. Bucco-lingual 
longitudinal section, showing 
root-canal. 



Fig. 534.— Inferior right sec- 
ond bicuspid. Base of pulp- 
chamber, showing entrance to 
rout-canal. 



PULPLESS TEETH AND FILLING PULP- CANALS. 433 

The second step in the treatment is to open the pulp-chamber and root- 
canals and remove all pulp debris. 

This is a simple matter in the superior incisor teeth, which have straight 
roots and normal canals, as shown in Figs. 514, 515, 516, and 517, which 
are longitudinal sections cut labio-liugually and mesio-distally. 

The canals of the inferior incisor teeth are more difficult to enter, by- 
reason of the mesio-distal flattening of their roots and the corresponding 
narrowing of the canals. This is shown in Figs. 518, 519, 520, and 521, 
sections cut in the same manner as those preceding. 

The cuspids, both superior and inferior, when the roots are straight, are 
as easily entered as the superior central incisors. Figs. 522 and 523 are 
sections of the superior cuspids, and Figs. 521 and 525 are sections of the 
inferior cuspids. Fig. 526 represents some of the peculiarities met with 
in the inferior cuspids and bicuspids. 

The superior bicuspids usually offer no serious difficulties in gaining 
access to their canals. It must be remembered, however, that the superior 
first bicuspid has usually a bifurcated root and two canals, as shown in 
Fig. 527 ; these are sometimes very small, — the labial root being the 
smallest, — and for that reason some difficulty may be experienced in fol- 
lowing them to the apical foramen. Fig. 528 shows the location of the 
pulp-canals at the base of the pulp-chamber. 

The superior second bicuspid has generally a single root and a single 
canal, which is of good size, as shown in Fig. 529, but it is often flattened 
mesio-distally. Fig. 530 shows the form and size of the pulp-canal at the 
base of the pulp-chamber. 

The inferior bicuspids are almost invariably single-rooted teeth, having 
a single canal, as shown in Fig. 531, which usually gives free access to the 
apex. Fig. 532 shows an inferior first bicuspid having two distinct root- 
canals. Their position, however, is sometimes such — being curved inward — 
as to make it difficult to readily open the canal, except with drills carried 
in the right-angle hand-piece. This difficulty is more often experienced 
in the first bicuspid than in the second. Figs. 533 and 534 show the form 
of the canals in the inferior second bicuspids. 

The superior molars offer somewhat greater difficulties to thorough open- 
ing of their canals, by reason of the angles of inclination of their roots 
and the differences in the size of the roots and their canals. The difficul- 
ties of gaining access to the canals increase from tooth to tooth in a distal 
direction, not so much from the shape and direction of the canals as from 
the position of the teeth, which makes it impossible to use straight instru- 
ments or to gain a view of the field of operation except by the reflected 
image. 

In the superior first and second molars the disto-buccal root is the only 
one which, as a rule, offers any considerable difficulty in locating and 
following the canal. Fig. 535 is a longitudinal section of the disto-buccal 
and lingual roots of a superior first molar, and Fig. 536 of a similar tooth 
cut so as to show the buccal roots. This canal is often so small that the 
finest Donaldson bristle cannot be made to enter it for more than a small 
fraction of the length of the root. Fig. 537 shows the size and form of these 

28 



434' OPERATIVE DENTISTRY. 

canals at the base of the pulp-chamber. The pulp-canals of the superior 
second molars are shown in Figs. 538, 539, and 540. The superior third 
molars are the most difficult to treat, but this is due more to their position 
than to any other reason. Fig. 541 is a longitudinal section of the mesio- 
buccal and lingual root of a superior third molar, and Fig. 542 of the' 
buccal roots of a superior third molar. Fig. 543 shows the size and form 
of the canals at the base of the pulp-chamber. Fig. 544, A and B, presents 
abnormal root-canals sometimes found in these teeth. 

The inferior molars when the canals are normal present no difficulties, 
as a rule, which are not readily overcome by a little skill and ingenuity. 
The difficulties, of course, are increased in operating upon the second and 
third molars over those of the first. Fig. 545 shows the pulp-canals in a 
mesio-distal longitudinal section of an inferior first molar. Fig. 546 shows 
the size and form of the canals at the base of the pulp-chamber. 

It should be borne in mind that the roots of the inferior molars are con- 
siderably flattened mesio-distally, that the canals are constricted in the 
centre, and that the mesial root and its canal are usually much smaller than 
the distal root and canal. 

Fig. 547 represents a mesio-distal longitudinal section of an inferior 
second molar, and Fig. 548 shows the size and form of the canals at the 
base of the pulp-chamber. Fig. 549 represents a mesio-distal longitudinal 
section of an inferior left third molar, and Fig. 550 shows the size and form 
of the canals at the ball of the pulp-chamber. Fig. 544, G, illustrates a 
not uncommon abnormality of the root-canals of an inferior third molar. 

The abnormalities in the number and the form Of the roots and pulp- 
canals are so many and so varied that a separate description of them 
would occupy too much space in a volume of this character. The accom- 
panying illustrations, Figs. 551, 552, 553, 554, 555, 556, and 557, and Plate 
VII., will, however, indicate the multiplicity and divergence of such abnor- 
malities, and will be a guide and a warning to the student that he will en- 
counter an uncertain number of teeth that will defy all efforts to follow 
their pulp-canals to the apex. 

Opening the Pulp-Chamber and Canals. — In opening the pulp- 
chamber and the root- canals of the teeth one general principle should be 
observed, — viz., to obtain access to the pulp-chamber in a direct line with the 
axis of the tooth. This rule holds good for any tooth in any part of the 
mouth. The operator should never attempt to gain access to the pulp- 
canals through an approximal, buccal, or lingual cavity of decay without 
extending it to a point which would give direct access, as it is impossible 
to thoroughly cleanse the canals or properly fill them through cavities of de- 
cay in these locations unless the above rule is observed. It is better practice 
many times to drill an opening in that portion of the tooth which will give 
direct access to the pulp-canal, treating it through this opening, and filling 
the cavity of decay without reference to its proximity to the pulp-canal. 

The superior and inferior incisors and cuspids should always be opened 
through the lingual surface, as this gives direct access to the canal, while 
the canals of the bicuspids and molars, both superior and inferior, should 
for the same reason be opened through the centre of the morsal surface. 



Disto-buccal 
root 




Lingual root 



Fig. 535.— Superior left first molar. Bucco- 
lingual longitudinal section, showing root- 
canals. 



io-buccal 


11 


root 




u 



Fig. 536. — Superior left first molar. Mesio- 
distal longitudinal section, showing buccal 
root-canals. 



Lingual root 




Mesio-buccal 
root 

Disto-buccal 
root 



Fig. 537.— Superior left first molar. Base of 
pulp-chamber, showing entrance to root- 
canals. 



Lingual root 




Disto-buccal 
root 




Fig. 538.— Superior right second molar. 
Bucco-lingual longitudinal section, showing 
root-canals. 



Fig. 539.— Superior right second molar. 
Mesio-distal longitudinal section, showing 
buccal root-canal. 



Lingual root 




Mesio-buccal 
root 



Fig. 540.— Superior left second molar. Base 
of pulp-chamber, showing entrance to root- 
canals. 



Lingual root 




Mesio-buccal 




Fig. 541. — Superior left third molar. Bucco- 
lingual longitudinal section, showing root- 
canals. 



Fig. 542.— Superior right third molar. Mesio- 
distal longitudinal section, showing buccal 
root-canals. 




Mesio-buccal 
Disto-buccal [g- t ■! root 
root |Pj 

Lingual root 



Fig. 543. — Superior right third molar. Base of pulp-chamber, 
showing entrance to robt-canals. 




Fig. 544.— A, superior third molar ; li, superior third molar ; C, inferior third molar. 




Distal 
root 



Q 



Mesial 
root 



545.— Inferior left first 

Mesio-distal longitu- 

section, showing root- 



Fig. 54C— Inferior left first 
molar. Base of pulp-chamber, 
showing entrance to root- 
canals. 




Fig. 547. — Inferior left second 
molar. Mesio-distal longitu- 
dinal section, showing root- 
canals. 



o 



Mesial 



Fig. 548.— Inferior left second 
molar. Base of pulp-chamber, 
showing entrance to root- 





^^ l 




m *%m 




I - M 


jsial 




root 


hM 



Fig. 549.— Inferior left third 
molar. Mesio-distal longitu- 
dinal section, showing root- 
canals. 



D 



Mesial 
root 

Fig. 550.— Inferior left third 
molar. Base of pulp-cham- 
ber, showing entrance to root- 
canals. 




-A, double-rooted superior lateral incisor; B. united superior central and lateral incisors; 
C, superior cuspid ; 1), double-rooted superior bicuspid. 



A 


B C 


I) K 






| 9 1 ffl 


Bf -'■ 


' ft Jj n J| 


M 



-A, D, superior cuspids; B, 



C, double-rooted superior cuspids 
bicusuid. 



mltiple-rooted superior 




Superior bicuspids. 




Fig. 554.— Superior bicuspid and molars. 




Fig. 555. — Inferior first bicuspids. 



1 J! f % 



Fig. 556.— Inferior molars and bicuspids. 



% if n 



Fig. 557. — Inferior molars. 



PULPLESS TEETH AND FILLING PULP-CANALS. 



435 



The most satisfactory instrument for making these openings is the spear- 
pointed drill, care being taken not to drive the drill beyond the floor of 
the pulp-chamber in those teeth which have multiple roots, as by so doing 
it might penetrate the bifurcation. In the superior first bicuspids and the 
molars generally this opening needs to be considerably enlarged in order 
to enter their root-canals, as they usually form divergent angles to the floor 
of the pulp-chamber. This enlargement may be accomplished with cross- 
cut fissure burs or cone burs. 

Enlarging the Pulp-Canals.— The question of the propriety of me- 
chanically enlarging the pulp-canals is one upon which there is a consid- 
erable difference of opinion. 
Fig. 559. Some operators claim that a 

perfect cleansing of the canals 
cannot be accomplished without 



Fig. 558. 

n 



Fig. 560. 






Gatos-Glidden 
drills. 



Donaldson 
Bristles. 



except by such preparation. 
Others maintain that any canal 
which will admit a Donaldson 
bristle (Fig. 558) can be per- 
fectly cleansed without enlarg- 
ing it, and those cases in which 
the canals are so small that they 
will not permit the bristle to 
enter need no cleansing or filling. 
1 The writer prefers a middle ground be- 

ll tween these two extremes. There is always 
I danger in extremes, both of theory and prac- 
|l| tice ; it is, therefore, better to try to avoid the 
lilii errors of over-enthusiasm, but keep so alert 
for the truth that it does not escape us. 

Nearly every pulp- canal that will permit 
the passage of a broach or a Donaldson bristle is placed in 
better condition for cleansing and filling by being opened 
and enlarged with a reamer or G-ates-Glidden drill (Fig. 
559) for at least a part of its extent ; but the dangers are 
so great, if the root is curved or very much flattened 
mesio-distally, of making an aperture through the side of 
the root, or near its apex, or of forcing septic material 
through the apical foramen, or breaking off the head of 
the drill and leaving it lodged in the canal, that these in- 
struments should be used with the greatest caution. Break- 
ing the drill while reaming the canal is much more liable 
to occur if the burring engine is used than when hand in- 
struments are employed. Swiss jewellers' broaches of spring temper are 
very valuable instruments for enlarging the pulp-canals and cleansing them 
of debris, and are much less liable to be broken and lodged in the canal 
than any other form of instrument. They cut much slower and do not clog 
so readily as the Gates-Glidden drill, and for these reasons, in small and 



Donaldson pulp- 
canal cleansers. 



436 



OPERATIVE DENTISTRY. 



constricted canals they are much the safest instruments to use. The break- 
ing of an instrument in a pulp-canal is an exceedingly vexatious accident, 



Fig. 561. 



-Drawn temper.^ 



Fig. 562. 
Spring temper.- 



\ 




Nerve extractors. 



as its removal often entails no inconsiderable amount of labor 
and the consumption of much valuable time. 

After the orifice of the pulp-canal has been sufficiently en- 
larged to suit the purpose, it should be thoroughly cleansed of all 
debris by the aid of the Donaldson pulp-canal cleansers (Fig. 
560) or the nerve extractors shown in Figs. 561 and 562. 

Hydrochloric and sulphuric acids are recommended by Calla- 
han and others for chemically enlarging the pulp-canals. These 
agents in twenty-five to fifty per cent, solutions are conveyed 
to the canals upon a platinum bristle or probe and carefully in- 
sinuated. The affinity of these acids for the lime-salts is such 
that the walls of the canals are rapidly softened and disinte- 
grated. The softened material is then readily removed with the 
Donaldson pulp-canal cleanser. The action of the acid may be 
limited by saturating the canals with a solution of sodium bicar- 
bonate. 

The third step in the operation is the local application of such 
therapeutic agents as possess germicidal, antiseptic, and disinfect- 
ant properties. These agents all have in common the property 
of destroying pathogenic and saprophytic micro-organisms, pre- 
venting the development of their spores, or of rendering inert or 
innocuous their waste products. They differ, however, very 
markedly in other respects ; for instance, some of them coagulate 
albumin, while others do not. The former are therefore classed 
as coagidants, the latter as non-coagulants. To the first class belong 
all of the salts of metals and the alcohols, to the second very 
many of the essential oils. The non-coagulants possess, in a great 
degree, the power of diffusion, and maintain their antiseptic 
properties for a longer j>eriod than the coagulants ; hence in the 
treatment of pulpless teeth these agents are considered by many 
operators to be more valuable for this purpose than the coagulants. 

The metallic salts, which possess decided germicidal antiseptic and dis- 



Nerve 

extractor 

with 

holder. 



PULPLESS TEETH AND FILLING PULP-CANALS. 437 

infectant properties, are the zinc chloride (ZnCl,), aluminum chloride 
(A1 2 C1 6 ), mercuric chloride (HgCl,), auric chloride (AuCL), sodium sul- 
phite (Na 2 S0 3 ), cupric sulphate (CuS0 4 ,5H 2 0), and the argentic nitrate 
(AgNOj) . These have all been tested as germicidal agents in the treatment 
of septic pulp-canals, but all except the zinc and aluminum chlorides and 
the sodium sulphite have been discarded on account of the discoloration^ 
which they produce. 

The alcohols which are commonly employed in the treatment of septic 
pulp-canals are the ethylic or commercial alcohol, phenylic alcohol, — viz., 
carbolic acid, — and creosote, with the coal-tar derivatives, the cresols. 

Formol is also a very valuable therapeutic agent for disinfecting septic 
pulp -canals. The forty per cent, solution is reduced to a solution of two 
to three per cent, for dental use. Stronger solutions are irritating and 
coagulating. 

The essential oils which are most in favor for the treatment of septic 
conditions of the pulp-canals are those of cloves, cinnamon, cassia, thyme, 
and eucalyptus. They are not, however, so powerful in their germicidal 
action as the coagulants. 

Certain mineral acids have also been recommended for this purpose,— 
viz., the hydrochloric and sulphuric acids. They destroy micro-organisms 
by their intense chemic action, while the alkalies which have been employed 
are a combination of potassium and sodium, — Schreier's alloy, known 
under the name of kalium-natrium, sodium carbonate (]STa 2 C0 3 , 10H 2 O), 
and sodium dioxide (Na 2 2 ). These agents act by saponifying the fatty 
matter formed by the decomposition of albuminous substances and dissolv- 
ing the albuminous substances contained in the pulp-canal. 

Oxygen and chlorine gases in the nascent state have also been employed 
for the purpose of rendering the pulp-canals and the dentin sterile. Oxy- 
gen is still extensively used. These agents are also employed for the pur- 
pose of bleaching discolored teeth, the process of sterilization, however, 
progressing with the penetration of their bleaching action. 

Oxygen gas is obtained by the introduction into the pulp-canals of 
aqueous and etherial solutions of hydrogen dioxide (H 2 2 ) or solutions of 
sodium dioxide (Na 2 2 ). These agents when placed in contact with de- 
composing albuminous substances give up one atom of their oxygen ; the 
liberated oxygen acting as an oxidizer. The former is decomposed into 
water and nascent oxygen, the latter into sodium hydroxide and nascent 
oxygen. 

Chlorine is usually employed in the form of hypochlorites, usually in 
solutions made by the electrolytic action of powerful electric currents upon 
sea- water. These preparations have the name of electrozone and meditrina. 

Iodine and bromine and their preparations are also powerful sterilizing 
agents. Iodine is usually employed in the form of the tincture. Iodol 
and iodoform are objectionable for use about the mouth on account of their 
disagreeable odor. 

Bromine is objectionable for the same reason, and also for its intense 
irritating effects. 

Aristol, which is a combination of thymol and iodine, — dithymol binio- 



438 OPERATIVE DENTISTRY. 

dide, — is a favorite remedy with many operators for sterilizing putrescent 
pulp-canals. Hydronaphthol and a number of similar agents have been 
recommended from time to time, and have been used with considerable 
success. 

Authorities differ as to the diffusibility of the coagulants. Some have 
maintained, notably Harlan,* that zinc chloride and carbolic acid, by 
their coagulating effect upon albumin, did not become diffused through 
the dentin ; while, upon the other hand, such authorities as Truman, f 
Kirk, X and York § have maintained an opposite view. 

Formol coagulates albumin, mucin, and gelatin, the coagulum main- 
taining its form for an indefinite period, and appears to be rendered per- 
manently sterile so far as the action of the organisms of decomposition are 
concerned. 

MATERIALS EMPLOYED FOR FILLING PULP-CANALS AND METHODS OF 
INTRODUCTION. 

The pulp-canals having been properly prepared and sterilized are now 
ready for the introduction of the material which is to occupy the space in 
the canals formerly held by the dental pulp. The main object sought in 
filling the pulp-canal is to hermetically close or seal the apical foramen, 
and thus to prevent the egress of septic material, mephitic gases, micro- 
organisms, or their waste products from the canal into the apical space, and 
also to preclude the possibility of the entrance by transudation of fluids 
from the apical tissues into the canal. These materials should be of such a 
character that they will remain unchanged by any influence which may be 
brought to bear upon them in such an environment. They must be unirri- 
tating to the soft tissues, impervious to moisture, susceptible of such ready 
adaptability to the walls of the canal as to insure a moisture-tight filling, 
and should possess antiseptic properties, or at least be capable of being 
rendered absolutely sterile when introduced. 

The materials which are used for this purpose may be divided into 
three classes, — viz., solids, plastics, and fluids. These materials are, however, 
often combined, the solids being used as the medium whereby the plastic 
and fluid substances are introduced into the canal.- The solid materials 
comprise gold-foil in various forms, tin-foil in shreds or pellets, gold and 
copper wire, lead and wood points, the latter made of hickory or orange- 
wood and saturated with creosote. 

The base metals, which are readily oxidized, have never been extensively 
employed on account of their liability to cause discoloration of the dentin, 
though from the therapeutic stand-point this quality sometimes renders 
them very valuable. The jflastic materials which are most commonly em- 
ployed are zinc oxychloride and softened gutta-percha points. Cotton, 
silk, and asbestos fibre are sometimes used as the vehicle for introducing 
zinc oxychloride and other plastic materials into the pulp-canal. The 

* Dental Review, vol. x. p. 44. 

t Proceedings Academy of Stomatology, Philadelphia, 1894. 

t Dental Cosmos, vol. xxxvi. p. 181. 

§ Transactions Illinois State Dental Society, 1897. 



PULPLESS TEETH AND FILLING PULP-CANALS. 



439 



objection to the use of a vegetable fibre like cotton as a filling for pulp- 
canals is overcome when it is employed in conjunction with the zinc 
chloride, "as it converts the cellulose of the cotton fibre into a pectous 
substance called amyloid, which is colorless and unchangeable in the 
conditions existing at the apex of a pulp-canal." * 

The fluid substances used for this purpose are gutta-percha — either the 
red base-plate or the white stopping — dissolved in chloroform, the familiar 
chlora-percha, and salol, and paraffin. The two latter substances are 
rendered fluid by heat before being introduced. On cooling they become 
hard. 

Fig. 563. 



II 



I I 




Pulp-canal pluggers. 



Fig. 564. 



Gold- foil was the first material used for the purpose of filling root- 
canals, and was introduced by the late Dr. Maynard, of Washington, D. C, 
about the year 1838. His method was to use narrow strips of heavy non- 
cohesive foil, and to pack this, into the canal with delicate pluggers (Fig. 
563) made for the purpose. When skilfully done it could 
be made to hermetically seal the apical foramen, but its 
removal, if circumstances required, was well-nigh impos- 
sible. For many years the older operators relied entirely 
upon this method of filling the pulp-canal. Tin is thought 
by some authorities to be Superior to gold, for the reasons 
that it is more easily introduced and when oxidized jdos- 
sesses antiseptic properties. 

Dr. W. S. How recommended the use of shredded tin 
for sealing the apical foramen. To avoid the danger of 
forcing the tin beyond the apical foramen a series of fine 
probes are used to measure the depth of the canal, as 
shown in Fig. 564, the clutch making it possible to meas- 
ure it exactly. With these probes the particles of 
shredded tin -foil are carried to the apex and impacted 
into position. 

This method is open to the same objection as gold, in 
that it cannot be removed from the pulp-cavity. The advocates of this 
method of filling pulp-canals assert that this objection is not a valid one, 




Canal probe gauge. 



Kirk, American Text-Book of Operative Dentistry, p. 325. 



440 OPERATIVE DENTISTRY. 

for if the canal lias been properly prepared aud sterilized and the material 
skilfully introduced such a necessity never arises. 

Gold, copper, and lead points are made by shaping sections of these 
metals to fit the caliber of the canal, the right length being ascertained by 
measuring the depth of the canal with a suitable probe or pulp-canal 
bristle. The late Dr. W. H. Morrison, of St. Louis, was the first to sug- 
gest the use of gold points for filling pulp-canals, which he recommended 
should be made from very soft pure gold wire shaped to fit the canal and 
of such length as not to pass the apical foramen when driven home. When 
introduced in conjunction with the plastic or fluid materials used for this 
purpose they can be made to perfectly seal the apical foramen as well as 
the entire length of the canal. 

Wood points are but little used at the present day, although thirty to 
thirty-five years ago they were for a time quite extensively employed. 
They had the advantage, when saturated with creosote, of remaining per- 
manently antiseptic, but there was no assurance that the apical foramen 
was hermetically sealed unless used in conjunction with the plastic mate- 
rials, or that when the point was driven into the canal it did not project 
beyond the apical foramen. 

Cotton saturated with creosote or carbolic acid was recommended many 
years ago as a permanent filling for pulp-canals by Dr. J. Foster Flagg, 
and for a long time it was extensively employed. It, however, did not 
fulfil the expectations of some of its most ardent advocates, especially 
when carbolic acid was used as the antiseptic, for pericementitis and 
alveolar abscess was not an infrequent sequel after a few months or years. 
When creosote was used the results were much better, as the antiseptic 
properties of this agent are more permanent. But neither carbolic acid 
nor creosote retain their antiseptic properties very long in such an environ- 
ment. At the present time this material is rarely used as a permanent 
pulp-canal filling unless combined with zinc oxychloride. Since the 
dentist is now supplied with materials which are so much more reliable 
for this purpose, there seems to be no excuse for using a material whose 
only qualification is that it can be easily introduced. 

The writer has removed many of the cotton fillings, and with few ex- 
ceptions — and these had been saturated with creosote — they were vile- 
smelling and disgusting, while some of them were saturated with septic 
matter, discolored, and positively rotten. 

Zinc oxychloride has been demonstrated by abundant clinical experience 
to be one of the most valuable of the materials employed for filling pulp- 
canals. When mixed to the consistency of a creamy paste it can be 
readily introduced into any accessible canal by the aid of a fine pulp-canal 
bristle and using a gentle pumping motion. Or it may be introduced 
upon fibres of cotton or silk. After it has set it is very hard, and has the 
advantage of remaining antiseptic for a considerable period thereafter, on 
account of the excess of the zinc chloride which is usually present in this 
cement. Care must be exercised not to allow the cement to pass the apical 
foramen, as it is very irritating to the soft tissues. Its peculiar coagulating 
and mummifying effect upon any remnants of the pulp and the contents of 



PULPLESS TEETH AND PILLING PULP-CANALS. 441 

the tubuli prevents decomposition of these tissues and preserves the 
normal color of the dentin. 

If the removal of the cement become necessary, it may be accom- 
plished with Callahan's method of enlarging pulp-canals with sulphuric 
acid. 

Gutta-percha is also one of the most valuable materials for filling pulp- 
canals, many operators preferring it to the zinc oxychloride. 

Gutta-percha cones of proper shape and length, made from either the 
base-plate or the white stopping, when rendered plastic by heat or the 
action of chloroform, the volatile extract of eucalyptus, or the oil of 
cajuput, are most easily and successfully introduced even into tortuous and 
very fine canals. If the pulp- canals are first filled with a thin solution of 
chlora-percha and the material worked as far towards the apex as possible 
with a fine Donaldson bristle, or if moistened with the volatile extract of 
eucalyptus, or the oil of cajuput, the surface of the gutta-percha point will 
be rendered plastic and antiseptic. After being carefully placed in posi- 
tion and warmed by a blast of heated air directed upon it from a hot-air 
syringe, it will, under a little pressure from the pulp-canal plugger, readily 
slip into place, sealing the apical foramen, and by adding other cones the 
entire caliber of the canal may be filled to the orifice. In tortuous canals, 
by a little extra pressure the fluid gutta-percha can be made to penetrate 
to the very apex. If the canal has been thoroughly dried before the intro- 
duction of the filling, the gutta-percha will adhere very closely to the walls 
of the canal. This material is unchangeable in such an environment, and 
is the most bland and non- irritating to the soft tissues of any of the ma- 
terials which are used for this purpose. It may be removed by first soften- 
ing it with chloroform, and then thrusting a barbed broach into it and 
twisting the broach as is done in extirpating a devitalized pulp. 

In the introduction of gutta-percha points care should be taken not 
to use so much force in packing them into place as to cause any portion to 
escape into the apical space. To prevent air being forced into the space 
by the introduction of the cone, the canal should be first filled with fluid 
chlora-percha and carefully worked to the apex with a fine probe. If the 
pressure is made gently and the patient warned to give notice as soon as 
the least sensitiveness is felt at the apex of the root, this accident may be 
avoided. This suggestion is applicable to the introduction of all forms of 
pulp-canal fillings. Pressure of the filling upon the tissues of the apical 
space, or the presence of air or septic debris forced through the foramen in 
front of the filling, always induces more or less pericemental irritation, and 
not infrequently results in alveolar abscess. 

Ottolengui suggests the preparation of gutta-percha points or cones with 
a strand of silk in the centre, so that if it become necessary to remove the 
filling it can be more readily done if the cones have been prepared in this 
manner. His method of preparing the cones is as follows : ' ' Take floss- 
silk and wax it thoroughly, after which dip it into chlora-percha and cut 
it into pieces about an inch long. These when dry give gutta-percha 
cones which have a strand of silk through them. They are readily packed 
into the canal, and the end, being allowed to extend beyond the orifice of 



442 OPERATIVE DENTISTRY. 

the Canal, is readily grasped, in case of need, with a pair of tweezers, 
whereupon the whole root- filling is easily withdrawn." 

Theo. von Beust,* of Dresden, Germany, suggests the following method 
of preparing cones for root-fillings : "Take fine silver wire of from 0.02 to 
0.05 millimetre in diameter, and cut from the different thicknesses of wire 
lengths to correspond to .the different sizes of root- canals. These are tapered 
and roughened and surrounded with a film of gutta-percha, making the 
point cylindrical or cone-shaped, very like the root-canal points bought at 
the depots. A hook is then turned at the end of the point which is to 
occupy the coronal portion of the pulp-cavity. This makes an ordinary 
root-canal point of gutta-percha with a core of wire in the centre and a 
hook at the large end." By this method it is possible to remove the root- 
filling entire, should occasion require, by simply grasping the hook with a 
pair of dressing forceps. The point is inserted in the canal after the 
manner already described for other gutta-percha points. 

Chlora-perclia has its chief value in that it is capable, while in the fluid 
state, of being introduced into portions of certain canals in which solid 
materials could not be made to enter on account of their extreme smallness 
or their tortuous course. It is valuable, also, as a lubricant for the gutta- 
percha and metal points, and for closing the interstices between these 
materials and the walls of the canal. 

In introducing chlora-percha into tortuous and very small canals, it 
should be made quite thin and worked towards the apex as far as possible 
with fine Donaldson bristles ; then, by the aid of the How probes or other 
suitable instruments, fine threads of base-plate gutta-percha may be warmed 
and packed into the canals until they are full, when, if the patient has 
given no response to the forcing of the gutta-percha into the canals, a large 
piece of gutta-percha base-plate may be warmed and packed into the bot- 
tom of the cavity, and this covered with a pledget of cotton large enough 
to fill the cavity ; then, with as large a plugger as will enter the cavity, 
pack the cotton, gently at first, and gradually increasing the force until the 
patient feels a slight pressure at the apex, when all further forcing of the 
material should cease, as this indicates that the chlora-percha has reached 
the apex of the canal. 

Dr. W. C. Barrett,! of Buffalo, some years ago most convincingly 
demonstrated that not only would the chlora-percha travel by this method 
to the very apex of the canal, but that it might also follow certain minute 
canals which sometimes connect the pulp with the pericementum at some 
distance from the apex of the root. 

Salol and paraffin have been so recently recommended as materials for 
filling pulp-canals that it is too early to pass judgment upon their utility or 
permanent value. They are both introduced in the same manner. A fine 
probe is first passed into the canal to the apex ; a portion of the agent to 
be used is then taken up between the points of a pair of dressing pliers 
and heated over an alcohol flame until it is melted. While still hot the 
pliers are inserted into the cavity of the tooth, beside the probe, and then 

* Items of Interest, October, 1900, p, 713. f Independent Practitioner. 



PULPLESS TEETH AND FILLING PULP-CANALS. 443 

opened. The fluid material immediately follows the probe to the apex of 
the canal, and on slowly withdrawing the probe while the material is still 
fluid it occupies the space of the probe and completely fills the canal. 
Some operators are in the habit of inserting a gutta-percha or a metal cone 
into the canal while the material is still fluid, thus insuring the material 
reaching the apex and perfectly filling the whole canal. This method has 
another advantage which gives it importance, — viz., if it become necessary 
to remove the filling, a blast of hot air from a chip-blower, or the contact 
of a hot instrument with the filling, will melt the material and permit the 
cone of gutta-percha or metal to be easily withdrawn. 

Paraffin does not change its conditions in such an environment ; but 
this does not seem to be the case with salol, as several reliable observers 
have claimed that it has disappeared from the canals in which it had been 
placed, probably by volatilization and diffusion through the dentin. 

If pericemental soreness should follow the permanent filling of the pulp- 
canal, and this not infrequently happens, it may be relieved by painting 
the gum over the affected tooth with a counter irritant like tincture of aco- 
nite and tincture of iodine, equal parts of each ; or chloroform may be 
added in the same proportions. 

Mummification of the Pulp. — It has been frequently noticed, as far 
back as the days when arsenous acid was employed to relieve hyper- 
sensitiveness of the dentin, that after a time the tooth became slightly 
discolored and all sensitiveness disappeared ; later, when occasion of- 
fered to open the pulp-chamber, the pulp was found not only dead, but 
completely desiccated or mummified, although in many of these cases no 
pericementitis was ever manifest. It has also been noticed, when por- 
tions of a pulp, devitalized by arsenous acid, had been left in the apex of 
the root, that very often such remnants, after having been treated with 
creosote or zinc chloride solutions, gave no further trouble whatever. The 
same conditions often occurred under fillings and cappings made of zinc 
oxychloride, and when the pulp-canals were opened, perhaps years after- 
wards, the pulps were found in a complete state of mummification. 

This was noticed also under amalgam fillings made of cadmium or con- 
taining large quantities of this metal. These facts have led many operators 
to experiment with various antiseptic agents in the hope of discovering 
some method whereby it would be possible to render such remnants of 
pulp-tissue, as must often be left in tortuous and crooked pulp-canals, per- 
manently aseptic, and thereby insure the possibility of its never causing 
pericementitis or alveolar abscess. 

Witzel (1874), according to Miller,* was the first experimenter to insti- 
tute systematic observations upon the subject. Witzel' s method was to 
devitalize the bulbous portion of the pulp by means of arsenous acid, ex- 
tirpate that part, and leave the portions in the canals undisturbed, treating 
these portions as freshly exposed pulps. This is the method followed later 
by Herbst, the only difference being that Herbst used native arsenic — 
cobalt — instead of the regular arsenous acid. 

* Proceedings Columbian Dental Congress, 1893. 



444 OPERATIVE DENTISTRY. 

A few cases treated after this manner do well, but the great majority of 
them sooner or later develop pericementitis and alveolar abscess. 

Miller found that only a very small number of the antiseptic agents 
have any permanent sterilizing action upon the pulp. These are the 
cyanide, bichloride, and salicylate of mercury, sulphate of copper, and the 
oil of cinnamon. The preparation which gave the best results was com- 
posed of mercuric chloride, 0.0075 gramme, and thymol, 0.0075 gramme, 
made into tablets. 

The method of employing this preparation is to devitalize the pulp 
and remove all that is readily accessible, then place one of the tablets in 
the pulp- cavity, crush it with an amalgam plugger, working it down into 
the canals as far as possible, and cover it with gold-foil. The great objec- 
tion to this preparation is that the mercuric salt discolors the tooth. 

This same experimenter expresses great faith in the power of the oil 
of cinnamon to permanently sterilize any fragments of pulp-tissue that 
may from necessity be left in the pulp-canals. The only objection to the 
use of this agent, and also of oil of cassia, is their liability to produce a 
greenish discoloration of the tooth. 

Continuing the same line of experimentation, Soderberg has found the 
following formula to be very efficacious as a means for permanent pulp 
sterilization : 

B Aluruexsic, 
Thymol, 

Glycerol, aa equal parts ; 
Zinc oxide, q. s. to make a stiff paste. 

Frith claims good results from the following formulae : 

R Tannic acid, 

Thymol, aa equal parts ; 

Glycerol, q. s. to make a stiff paste. 

R Mercuric chloride, 
Thymol, 

Acidi carbolici, aa. 2 grammes ; 
Acidi tannici, 

Morph. mur., aa 1.5 grammes ; 
01. menth., 
01. cassia?, aa q. s. to make a stiff paste. 

With the latter ' ' a tannate of mercury is formed ; it is insoluble, and 
but little pain is caused by its absorption." 

The method of applying these sterilizing agents is to remove all of 
the pulp-tissue that is possible, then to place a portion of the paste 
in the pulp-chamber and with a root-canal plugger carry it into the 
canals, and then add enough more to fill the pulp-chamber, cover it 
with zinc oxyphosphate, and fill with gold or amalgam as the conditions 
require. 

Soderberg has more recently suggested that a small quantity of cocaine 



PULPLESS TEETH AND FILLING PULP- CANALS. 445 

be added to the paste to prevent the pain incident to the action of the 
dried alum upon the pulp -tissue. 

Objections have been raised to the employment of such methods of 
treatment, for the reason that it was feared it would tend towards slovenly 
methods of operation, as it would be much easier to apply the paste than 
to carefully follow the pulp -canals until all remnants of pulp -tissue that 
skill and patience could reach were removed. The advantages of the 
method lie in the possibility of so sterilizing the remnants which cannot 
with the utmost skill be removed that there will be little or no probability 
of their ever causing future trouble. 



CHAPTEE XXVII. 

BLEACHING DISCOLORED TEETH. 

Discoloration of a tooth, is the result of the death of its pulp, the dis- 
organization of the red blood- corpuscles, and the dissemination of the 
hsemoglobin through the dentinal tubuli. It should be understood, how- 
ever, that in this connection no reference is made to those metallic stains 
resulting from the oxidation of amalgam fillings containing large amounts 
of silver or cadmium, or from other conditions which may be operative 
in the mouth, like the chromogenic action of certain bacteria, tobacco, 
medicines containing iron, etc. Chemistry has not as yet discovered any 
reliable and effective method of removing the metallic stains caused by 
the oxidation of metal fillings, etc. 

The death of the pulp does not of necessity result in discoloration of 
the tooth, but loss of its translucency or vital appearance is always a re- 
sultant of pulp devitalization. This appearance once lost can never again 
be restored by any means known to chemistry or dental art. Discolora- 
tion may be removed and the tooth whitened, but a natural appearance in 
color or translucency can never be obtained. The removal of discolora- 
tion may be accomplished by two methods : first, by chemic agents, and 
secondly, by the color effect obtained by the introduction of a white filling- 
material into the enlarged cavity and pulp- canal. By such means it is 
possible to greatly improve the color, and this improvement is most marked 
in those teeth which are most discolored. 

The first noticeable change in the color of a tooth which has had its 
pulp devitalized by any of the various causes which may produce this 
condition is that of a pinkish tint. 

The discoloration in devitalized or pulpless teeth ranges from a pinkish 
tint to black. These gradations in color pass rapidly ' ' from the original 
pinkish, hue, which becomes yellow ; this, growing darker, passes into 
brown, and after the lapse of considerable time the tooth may become a 
permanent slaty gray or black." (Kirk.) 

It is a notable fact, however, that the character of the agency which 
has caused the devitalization of the pulp determines to a considerable de- 
gree the rapidity with which discoloration of the tooth ensues. Trauma- 
tisms which produce severe injury to the pulp, rupturing its blood-vessels 
and causing extravasation of blood into its tissues, result in almost imme- 
diate discoloration of the tooth. Intense irritation, such as is produced by 
the application of arsenic trioxide, zinc chloride, or other violent irritants 
which cause infarction, embolism, or thrombosis, sometimes result in dis- 
coloration in less than twenty-four hours after their application. A severe 
pulpitis, lasting for two or three days before the vitality of the pulp is 
destroyed, does not cause discoloration nearly so readily ; while if the in- 
flammation has been of a mild type and the devitalization of the pulp has 
446 



BLEACHING DISCOLORED TEETH. 447 

progressed slowly, the initial discoloration may be so slight as to escape 
notice except by reflected light. 

If, however, the devitalized pulp is permitted to remain in the tooth 
for any length of time the color gradually grows darker, and although 
it may never become so unsightly as those which have been devitalized 
by more violent irritants, they will in time assume a color which will call 
for treatment to render them less conspicuous. Teeth, however, in which 
the pulp has been removed immediately after devitalization, or while it is 
in a state of irritability, but before stasis, embolism, or thrombosis has 
occurred, do not, as a rule, become discolored. The only change noticed 
in them is the loss of translucency. 

Pathology. — Black has found the coloring matter of the red blood- 
corpuscles in a crystalline form in the blood- clots found in devitalized 
pulps, and that while the clots are in a state of solution from disintegra- 
tion the coloring matter may enter the tubules in large amount and cause 
the discoloration of the entire dentin, giving it a red color. 

The decomposition of the proteid elements of the pulp exerts a pro- 
found modifying influence upon the extent and the intensity of the dis- 
coloration by the formation of hydrogen sulphide and its action upon the 
haemoglobin. 

Healthy blood contains on an average twelve per cent, of haemoglobin. 
(Vaughn.)* The crystals of haemoglobin have the bright red color of arte- 
rial blood ; this explains the initial pinkish hue or the red color which 
obtains in certain teeth immediately after devitalization of the pulp. 
Haemoglobin has the power of forming rapid association and dissociation 
with oxygen without affecting the molecular arrangement of the haemo- 
globin itself. In fact, it is the oxygen carrier of the red blood-corpuscle. 
Haemoglobin is a proteid body combined with haematin, a body of known 
composition containing iron ( C M H 35 N 4 Fe0 5 ). 

The term oxyhemoglobin is used to designate the haemoglobin while it 
carries the oxygen, and in contradistinction to the haemoglobin from which 
the oxygen has been removed. Arterial blood contains a considerable 
quantity of oxyhemoglobin, but very little reduced haemoglobin ; while 
venous blood is poor in the former and rich in the latter. ("Vaughn. )f 

The association of oxygen with haemoglobin, although a chemic com- 
bination, is of such a nature that the oxygen is readily given up and 
replaced without detriment to the haemoglobin molecule. The red blood- 
corpuscle is therefore able to receive its oxygen as it passes through the 
pulmonary circulation, and give it up again in its passage through the 
capillary system, without material change in the corpuscle itself. 

No accurate formulae have been found for the proteids. Bunge gives 
the following analysis as the range of variation in their composition : 

• Carbon 50.0 to 55.0 per cent. 

Hydrogen 6.6 to 7.3 per cent. 

Nitrogen 15.0 to 19.0 per cent. 

Sulphur 0.3 to 2.4 per cent. 

Oxygen 19.0 to 24.0 per cent. 

* Chemical Physiology and Pathology. f Ibid. 



448 OPERATIVE DENTISTRY. 

According to Wurtz their composition is as follows : 

Carbon 52. 7 to 54.5 per cent. 

Hydrogen 6.9 to 7.3 per cent. 

Nitrogen 15.4 to 17.0 per cent. 

Oxygen 20.9 to 23.5 per cent. 

Sulphur 0.8 to 2.2 per cent. 

It will be seen, therefore, that according to the analysis of Bnnge the 
albumins contain approximately from 6.6 to 7.3 per cent, of hydrogen and 
from 0.3 to 2.4 per cent, of sulphur, while those of Wurtz place the per- 
centage of hydrogen at 6.9 to 7.3 and sulphur at 0.8 to 2.2 per cent. 

In the putrefaction of the animal albumins these substances are decom- 
posed into fat, tyrosin, leucin, ammonia, hydrogen sulphide, carbon dioxide, 
hydrogen, and nitrogen. The hydrogen sulphide is formed by. the union of 
two atoms of hydrogen with one of sulphur. This gas acting upon the 
haemoglobin and certain of its compounds, formed by decomposition, — viz., 
methaeinoglobin, hsemin, haematin, and haematoidin, — present various chro- 
mogenic features which explain the color changes that take place in the 
tooth during the decomposition of the albuminoid substances of the pulp, 
the organic material of the dentin, and the haemoglobin of the blood con- 
tained in this organ at the time of its devitalization. These compounds 
form various colors. The crystals of haemoglobin are bright red ; those of 
methcemoglobin are reddish brown ; those of hcemin are dark brown or black ; 
those of hcematin are bluish black ; and those of hcematoidin are reddish or 
orange-colored. 

" Extravasations of blood quickly undergo changes which are visible 
even to the naked eye. In the skin they are at first brownish, then blue- 
green and yellow. When small hemorrhages have occurred in the sub- 
stance of a tissue, as the periosteum, pleura, or lung, reddish-brown or 
blackish spots will be visible long afterwards. In bodies which are rapidly 
putrefying these areas may be slate- colored. 

1 i Larger hemorrhages into the tissues — for example, in the brain or the 
lung — come to have a rusty color after a time, and still later the affected 
spots show ochre-yellow, yellowish-brown, or brown pigmentation. Corre- 
sponding with all these changes in color are physical and chemical changes 
in the haemoglobin and in the iron contained in it." * 

During the process of disintegration of the red corpuscles of the blood 
the haemoglobin breaks up into "two groups of substances, one containing 
iron and the other not ; the former is called hwmosiderin, the latter hcema- 
toidin." f 

Hcematoidin is chemically identical with bilirubin, the chief coloring 
matter of the bile ; and, as already noticed, it is reddish or orange-colored 
in its crystalline form. " It appears to be more abundant when the blood- 
pigment is not much exposed to the action of living cells, as in the centre 
of large extravasations, and in hemorrhages into preformed cavities of the 
body, as, for example, into the pelvis of the kidney or into the subdural 
space." X For this reason it would seem that the same conditions would 

* Ziegler, General Pathology, 1899. f Ibid. J Ibid. 



BLEACHING DISCOLORED TEETH. 449 

obtain in a closed cavity like the pulp-chamber, which had not been pene- 
trated by caries or traumatism, and which would, upon the devitalization 
of the pulp, be devoid of living* cells in contact with it, and would thus 
explain the reddish or reddish- yellow discoloration of the teeth. 

"Hemosiderin, the derivative of haemoglobin containing iron, is met 
with in the tissues for the most part in the form of yellow, orange, or 
brown masses and granules, which deepen in color with time. ... If 
hemosiderin comes in contact with ammonium sulphide (or hydrogen sul- 
phide, both of which are derivatives of the putrefactive decomposition of 
the animal albumins), it becomes black by the formation of iron sul- 
phide." * 

The conditions for the formation of iron sulphide are present in a tooth 
containing a dead and putrefying pulp, and it may be safely inferred that 
this process takes place within the tooth as the result of the chemic 
changes which are brought about through the agency of the saprophytic 
micro-organisms acting upon the proteid elements of the pulp-tissue, the 
blood, the contents of the tubuli, and the hseniatin contained in the red 
corpuscles, the sulphur combining with the iron in the haematin to form 
iron sulphide. Kirk f is of the opinion that u while iron sulphide as such 
cannot be held wholly accountable for the final bluish-black color of a 
tooth which has reached the stage of permanent discoloration, the pig- 
mentation is almost certainly due either to it or to some allied compound 
in which iron and sulphur, with some organic constituents, largely enter, 
and which by a further slight decomposition would yield true iron sul- 
phide." 

PREPARATION OF THE TOOTH FOR BLEACHING. 

Various chemic agents have been suggested for the purpose of bleach- 
ing discolored teeth and restoring them to their normal color. The majority 
of these agents are more or less irritating and escharotic, and more or less 
injurious to the surrounding soft tissues ; it is therefore important that the 
tissues of the apical space should be protected by the introduction of a 
filling that will hermetically seal the apical foramen, and at the same time 
of such material that it will not be acted upon by the chemic agent em- 
ployed. The only material used for filling teeth that possesses these quali- 
ties is gutta-percha. To protect the gums, lips, and other soft tissues of 
the mouth, and the adjoining teeth, from the destructive action of these 
chemic agents the rubber-dam is of the greatest value ; in fact, it is indis- 
pensable. 

The first step in the preparation of a tooth for the bleaching process — a 
superior central incisor, for instance — is to freely open the pulp-canal and 
remove any remaining portions of the pulp and other debris by means of a 
Donaldson pulp-canal cleanser. This is to be followed with repeated irri- 
gations with sterilized water rendered alkaline by the addition of a small 
quantity of sodium bicarbonate. The cavity of decay, if one exists, 
should now be cleaned of all deeply stained softened dentin, and the pulp- 

* Ziegler, General Pathology, 1899. 
t American Text-Book of Operative Dentistry. 
29 



450 OPERATIVE DENTISTRY. 

chamber and canal enlarged with suitable burs and reamers. If perice- 
mental irritation exists, this condition must first be abated. 

The rubber dam should now be adjusted, but to the tooth only that is 
to be operated upon, as by this means there is less danger from leakage 
than when two or more adjoining teeth are included in the dam, while the 
adjoining teeth are protected against injury from any disintegrating or 
solvent action upon the enamel which might be possessed by the chemic 
agents used for the purpose of bleaching. To secure the dam from slip- 
ping off the tooth, and to guard against every possibility of leakage, a 
waxed ligature should be wrapped three or four times about the tooth at 
the cervix and tied with the surgeon's knot. Added security may be ob- 
tained by coating the ligature, — after it is in place, — the cervix of the tooth, 
and the rubber dam at this point with liquid chlora-percha. 

The cavity and the pulp-canal should now be dried with bibulous 
paper and amadou as thoroughly as may be with these absorbent agents, 
and further dehydrated by means of a Wooley or an Evans root-dryer or 
the hot-air syringe. The root-canal should now be filled with gutta-percha, 
which should not include more than the apical third or half of the canal, 
for the reason that the discoloration of the tooth is most intense at the cer- 
vix and immediately beyond towards the aj>ex, and if, as frequently hap- 
pens, there is recession of the gum, it is important that the bleaching 
process be carried beyond this point. 

All fillings of every kind which may be present in the tooth- crown 
should be removed before the bleaching process is commenced. This is 
especially necessary if the bleaching agent to be employed is one that con- 
tains chlorine, as this element readily combines with iron, gold, platinum, 
and other metals, forming soluble chlorides which, if permitted to penetrate 
the tubular structure of the dentin, will cause permanent discolorations 
that are well-nigh impossible to remove. For this reason, also, the instru- 
ments which are used for mixing and introducing bleaching agents of this 
character should be made of wood or ivory. Another advantage in re- 
moving the fillings from such a tooth is the increased surface which is 
thus exposed to the action of the bleaching agent. 

The cavity should next be thoroughly prepared by removing all remains 
of softened dentin, thin walls of enamel, and any septic or other foreign 
substance. Kirk recommends washing the cavity after it is prepared with 
dilute ammonia water, or a hot solution of borax in distilled water in 
the proportion of one drachm to one ounce, to saponify and remove by 
solution all fatty matters which might otherwise obstruct the entrance of 
the bleaching agent to the tubular structures of the dentin. The surplus 
moisture should next be removed, and the tooth is then in condition for 
the bleaching process. 

Method of bleaching Teeth. — The chemic agents which have been 
most successfully used for the purpose of bleaching discolored teeth are of 
two classes, — oxidizing agents and reducing agents. The former destroy the 
color molecule by virtue of their power to evolve oxygen in a nascent state. 
The latter act in an opposite manner by virtue of their great affinity for 
oxygen, seizing upon the oxygen element of the color molecule to form by- 



BLEACHING DISCOLORED TEETH. 451 

products, the character of which depends upon the chemic composition of 
the reducing agent employed. 

The oxidizing agents are divided into two forms, — viz., indirect oxidizers 
and direct oxidizers. 

The indirect oxidizing agents which are employed for bleaching teeth 
are chlorine in the form of chlorinated lime, chlorinated soda (Labarraque's 
solution), aluminum chloride, free chlorine gas, and iodine and bromine ; the 
latter being used to remove various special metallic stains. 

The direct oxidizing agents are hydrogen dioxide, sodium dioxide, and 
potassium permanganate. 

The reducing type of bleaching agents is represented by sulphurous 
acid. 

Chlorine Methods. — Chlorine (CI) has a strong affinity for all metallic 
substances, and under favorable circumstances enters with great energy 
into direct combination with them, forming compounds which are generally 
soluble in water. 

One of the chief characteristics of chlorine is its strong affinity for 
hydrogen (H) wherever found. This peculiarity is utilized in the opera- 
tion of bleaching teeth by liberating the chlorine which is held in combina- 
tion with the calcium, sodium, and aluminum of the above-mentioned 
compounds. The bleaching power of the chlorine is exerted upon the 
color molecule by seizing upon its hydrogen element and liberating the 
oxygen (O) contained in it. The oxygen thus liberated is in the nascent 
state, and in this form it acts most powerfully as an oxidizing agent. By 
the union of the chlorine with the hydrogen element of the color molecule, 
or other molecules containing hydrogen, chlorhydric acid (HC1) is formed, 
and the identity of the substance acted upon is destroyed. 

The Truman Method. — Dr. James Truman (1864) introduced the 
first successful method of bleaching discolored teeth. His method consists 
substantially of liberating chlorine from chlorinated lime by the addition of 
a weak solution of acetic, tartaric, or oxalic acid. Dr. Truman has sug- 
gested several ways by which the chlorinated lime and the acid may be 
brought together. "One process is to saturate the entire canal and the 
pulp-chamber with the acid before inserting the chlorinated lime ; another 
is to dip the instrument in the weak solution of acid, and then in the lime, 
and pack it rapidly into the cavity ; and still another is to make a paste 
by the use of distilled water, and pack this into the tooth, and then apply 
a stronger acid solution by means of cotton wrapped around the point 
used." * 

The cavity is then quickly sealed with gutta-percha, zinc oxychloride, 
or zinc oxyphosphate. This method to be repeated every two or three 
days until the required shade is obtained. 

The failures which occur by the use of this method are due, in the 
opinion of Dr. Truman, to defective manipulation, principally in the em- 
ployment of steel or any metal instruments, — as by their use metallic com- 
pounds are formed with the chlorine and permanent discolorations result, — 

* American System of Dentistry. 



452 OPERATIVE PENTISTRY, 

and in the non- employment of distilled water in the various manipulations, 
for reasons that are manifest. 

After the desired color is obtained, the tooth must be filled with some 
material which will by its antiseptic and coagulating qualities prevent the 
future decomposition of the contents of the dentinal tubuli. Dr. Truman 
thinks zinc oxychloride possesses these qualities in a remarkable degree, 
and experience proves it to be a most satisfactory substance for this purpose. 
After the cement has set it should be protected with a gold filling. 

In the employment of chlorinated soda for the purpose of bleaching a 
tooth, the dentin is dehydrated as thoroughly as possible by the usual 
means, and afterwards saturated with the solution. A piece of absorbent 
cotton may then be saturated with a weak acid solution, placed in the 
cavity, and sealed in. The chemical action is substantially the same as 
when chlorinated lime is employed, — viz., the liberation of chlorine which 
combines with the hydrogen element of the color molecule, and sets free 
the oxygen element in a nascent state. 

Another method of bleaching teeth with chlorine is that invented by 
Dr. Wright, of Richmond, Virginia. This method consisted of forcing a 
continuous stream of chlorine gas — previously prepared in the laboratory 
— into the pulp -canal and cavity of the tooth by an elaborate apparatus 
made especially for the purpose. The method was very efficient and rapid 
in its action, but the complications of the apparatus and the trouble of 
preparing the gas were obstacles which prevented its general adoption, 
and it was therefore abandoned. 

Dioxide Methods. — Hydrogen dioxide (H 2 2 ) is one of the class of 
direct oxidizing agents. Its value as a bleaching agent lies in the fact that 
one of its atoms of oxygen is bound to the water molecule by such a weak 
chemic combination that it is readily disrupted, and one of its atoms of 
oxygen liberated, as nascent oxygen. Many substances are capable of 
disrupting this compound and converting it into water (H 2 0) and free 
oxygen (O). Contact with fresh blood, pus, salivary secretions, inspis- 
sated mucus, albumin, and nearly every form of dead organic matter, 
causes disruption of the compound, the evolution of oxygen, and the 
decomposition, wholly or in part, of the organic matter with which it 
comes in contact. These characteristics make it not only a very valuable 
means for bleaching discolored teeth, but also as a cleansing agent and 
germicide in all operations upon the teeth and in diseased conditions of 
the mouth. 

The ordinary three or four per cent, aqueous solutions of hydrogen 
dioxide are of little value for the purpose of bleaching the teeth, as they 
are very unstable if kept for any length of time. 

Since the introduction of the ethereal solution prepared by McKesson 
and Bobbins, of New York, known as " caustic pyrozone," which contains 
twenty-five per cent, of hydrogen dioxide, the question of bleaching by 
the direct method has been solved, and this preparation is now largely used 
when this method is employed. 

The process of bleaching by this method is to apply the twenty-five 
per cent, ethereal solution to the pulp -canal and the cavity by means of 



BLEACHING DISCOLORED TEETH. 453 

loosely twisted wisps of cotton, and following each application with blasts 
of heated air from the hot-air syringe until complete evaporation of the 
menstruum is obtained. This process is repeated two or three times at the 
same sitting, or until the desired restoration of color is secured. Failing 
in this, an application of pyrozone may be sealed in the cavity and per- 
mitted to remain for one or two days, when upon removing it and making 
another application and evaporating it to dryness the color will usually be 
restored. 

The pyrozone seems, from experience, to act more rapidly and its re- 
sults to be more permanent if it has been rendered alkaline before apply- 
ing it "by the addition of a few drops of ammonice fortior, or by the solu- 
tion of one of the caustic alkalies, — e.g., sodium or potassium hydroxide 
or sodium dioxide." * 

Dr. D. N. McQuillen, of Philadelphia, has suggested the treatment of 
the pulp-canal and cavity with Schreier's kalium-natrium preparation to 
secure the alkaline effect in the process. The debris caused by the action 
of the kalium-natrium is then carefully removed with instruments and 
pellets of cotton, the usual washing omitted, and the pyrozone applied as 
above. 

This method gives most excellent results, both in the greater rapidity 
with which the bleaching process takes place and in the permanency of 
the results. As soon as the desired restoration of color is obtained the 
tooth should be filled temporarily with some material which can be easily 
removed, so that if discoloration returns the bleaching process may be 
again applied with little loss of time. No tooth which has been bleached 
should be permanently filled for at least two or three months, or even 
longer, that the permanency of the restored color may be assured before 
this operation is undertaken. 

Dr. A. W. Harlan, of Chicago, introduced the use of aluminum chloride 
in connection with hydrogen dioxide. His method is to pack the aluminum 
salt into the cavity and then to moisten it with hydrogen dioxide. This 
was originally thought to be a chlorine process, whereby the chlorine in 
the aluminum salt was liberated by the action of the hydrogen dioxide ; 
but later experimentation has shown that the reaction is due to the cata- 
lytic action of the aluminum salt, and that the hydrogen dioxide compound 
is disrupted by contact with the former and nascent oxygen is set free. 
Kirk suggests that inasmuch as aluminum chloride is an active coagu- 
lant, it is contraindicated in the bleaching of teeth until the process has 
reached the stage where a fixative is needed to prevent further decomposi- 
tion in the tubular structure of the dentin. 

Sodium dioxide (lSTa 2 0,) is another of the class known as direct oxidizing 
agents. It is similar to hydrogen dioxide in that its combination with one 
of its atoms of oxygen is so weak that it readily gives it up when subjected 
to the same conditions that cause hydrogen dioxide to part with one of its 
atoms of oxygen. The essential difference, however, lies in the character 
of the by-products which are formed after its decomposition. 

* Kirk, American Text-Book of Operative Dentistry. 



454 OPERATIVE DENTISTRY. 



its atoms of oxygen it becomes Na 2 0, still retaining its caustic and alkaline 
properties. When combined with water it is the ordinary caustic soda. 
The value which is possessed by sodium dioxide as an oxidizing or bleach- 
ing agent lies not only in the fact that its liberated atom of oxygen attacks 
the color molecule, but that it possesses great saponifying powers, which 
reach the oils and fats contained in the structures of the tooth and dissolve 
any organic matter still remaining. 

" For use as a bleaching agent it is applied to the dentin in a saturated 
solution. In making the solution especial care is necessary in order to 
avoid elevation of temperature, by reason of the energy with which it 
enters into combination with the water. If the solution is allowed to 
become heated in the making, decomposition of the compound with loss 
of oxygen occurs and its bleaching power is destroyed. The solution is 
best made by pouring into a small beaker, of about one ounce capacity, 
two drachms of distilled water and immersing the beaker in a large vessel 
or dish containing ice-water or pounded ice. The can containing the 
dioxide powder should then have its lid perforated with a number of small 
holes similar to the lid of a pepper caster, and the powder be slowly dusted 
into the distilled water in the small beaker. The powder is added to the 
water until the solution assumes a semi-opaque appearance, indicating the 
point of saturation. On removing the beaker from the cooling mixture, 
the dioxide solution will in a few minutes assume a transparent straw- 
colored appearance and be ready for use." * 

The method of application is similar to that employed when hydrogen 
dioxide is used, with the exception that pieces of asbestos felt are used 
instead of cotton with which to make the application, as the cotton fibre 
is acted upon by the sodium dioxide and converted into an amyloid sub- 
stance which interferes with the bleaching process of the solution. 

After the dentin has been thoroughly saturated with this solution a ten 
per cent, solution of sulphuric acid is applied, which neutralizes the alka- 
line condition, causing effervescence and the formation of sodium sulphate 
and hydrogen dioxide. 

The particular value of this method lies in the fact that it not only 
destroys the integrity of the color molecule, but the caustic alkali exerts 
a solvent action upon the organic material remaining in the dentinal 
tubuli, while the reaction which causes effervescence in the tubuli com- 
pletely removes the debris by mechanically forcing it out of the tubuli. 

It may be necessary to reapply the sodium dioxide, as one application 
does not always restore the color. Before doing this, however, the tooth 
should be thoroughly washed with hot distilled water. In the second appli- 
cation the acid should be omitted. After the color is restored the tooth 
should be again thoroughly washed with hot water to remove all debris, 
and after thorough desiccation the tooth is ready for the filling. Kirk 
recommends varnishing the walls of the cavity before introducing the fill- 
ing. Zinc oxychloride and zinc oxyphosphate cements are the best for 

* Kirk, American Text-Book of Operative Dentistry, p. 437. 



BLEACHING DISCOLORED TEETH. 455 

these fillings on account of their better color, while the zinc chloride by 
its coagulating effect will effectually prevent putrefactive changes taking 
place in any portions of organic matter which might remain in the tubuli. 

Kirk claims for this method that it not only restores the color of the 
tooth but normal translucency as well, and he thinks the opaque, white 
effect which results from other methods is due to the bleached organic 
debris remaining in the tubuli, while in the sodium dioxide method this 
is removed by the solvent action of the strong caustic alkali. 

Sulphurous Anhydride Method. — Sulphurous acid (sulphurous anhy- 
dride, SC 2 ) is the only one of the class of reducing agents that is used in 
the operation of bleaching teeth. Its value as a bleaching agent resides 
in its strong affinity for oxygen. When applied to a discolored tooth, it 
decomposes the color molecule and combines with its oxygen element, thus 
destroying the identity of the molecule and of the color. Various methods 
have been suggested for utilizing the bleaching property of sulphurous acid 
by the direct application of the gas to the root-canal of discolored teeth. 

One of these methods comprehended making a solution of the gas in 
water and applying the solution to the pulp-canal and the cavity. Another 
was to ignite, by means of the electric cautery, a small piece of sulphur 
which had been placed in the pulp- canal. Both of these methods are open 
to serious objections from the disagreeable odor and from their limited 
efficiency. To be efficient the gas must be confined within the cavity for 
some time, and with neither of these methods is such confinement possible. 

Kirk * has devised a method whereby it is possible to generate the gas 
from compounds placed within the pulp-cavity, and confine it there as in 
the chlorine process of Dr. Truman. The bleaching compound is made 
as follows: u One hundred grains of sodium sulphite and seventy grains 
of boric acid are separately desiccated and afterwards ground together in a 
warm, dry mortar. The x>owder is then to be transferred to a tightly 
stoppered bottle. For bleaching purposes the powder is packed into the 
root-canal and cavity of the tooth, and then moistened with a drop of water, 
and the cavity immediately closed as tightly as possible with a stopping 
of gutta-percha, previously prepared and warmed. A reaction ensues 
between the boric acid and the sodium sulphite whereby sulphurous acid 
is liberated. The process is effective in many cases where the chlorine 
methods have failed, but is slow in its action, and is largely superseded by 
the dioxide-of-hydrogen and dioxide-of-sodium methods." 

Cataphoric Method. — In the bleaching of the teeth by the cataphoric 
method the power of the continuous galvanic current to disseminate, dif- 
fuse, and carry remedies into and through animal tissues is taken advan- 
tage of to bring about a more complete and perfect dissemination of the 
certain bleaching fluids used to restore the color of devitalized teeth. 

The same electric apparatus and appliances employed in the treatment 
of hypersensitive dentin are used in this method of bleaching teeth. The 
principles involving the application of the current and its control are also 
the same (see Chapter XIII. ), the only difference being that the resistance 

* American Text-Book of Operative Dentistry, p. 439. 



456 



OPERATIVE DENTISTRY. 



offered by a devitalized tooth is much greater than that of a vital tooth, 
which necessitates a much higher voltage (pressure) to carry the bleaching 
agent into the dentin. While a current pressure of ten volts is all that 
can be utilized in the treatment of hypersensitive dentin, twenty-five to 
thirty, and even sixty volts, are sometimes required to drive a current of 
one and one-half milliamperes through devitalized dentin. 

The bleaching fluid which is used in connection with the galvanic cur- 
rent is a twenty-five per cent, aqueous solution of hydrogen dioxide to 
which has been added a small quantity of sodium chloride, sufficient to 
give it the strength of the normal salt solution used in transfusion, — one 
drachm to a pint of warm sterilized water, — as the addition of this salt 
increases the conductivity of the fluid. The ethereal solution of hydrogen 
dioxide is too resistant to the current to be utilized in this connection. 

To prepare a twenty-five per cent, aqueous solution of hydrogen diox- 
ide, place in a test-tube one volume of normal salt solution and two volumes 
of twenty-five per cent, ethereal solution of hydrogen dioxide, and mix by 
shaking the test-tube. To remove the ether, place the solution in a small 
porcelain evaporating dish and gently heat over a water-bath until the 
ether is all evaporated, care being used not to allow the flame of the lamp 
to ignite the ether vapor. The hydrogen dioxide is thus 
dissolved in the water and the ether dispelled. Dr. 
Hollingsworth recommends adding one per cent, of zinc 
sulphate to the solution, which diminishes the resistance 
and exerts a coagulating effect upon the organic matter 
of the dentin, which gives translucency to the dentin and 
enhances the permanency of the operation. 

The same care must be exercised in isolating the 
tooth by the rubber dam, and securing it against leakage 



Fig. 565. 




exercised in the treatment of hypersensitive dentin as 
already described in detail in the chapter previously 
referred to. 

The tooth being ready for the bleaching process, the 
aqueous solution of hydrogen dioxide is applied to the 
tooth-cavity on a pledget of cotton, which must at all 
times be kept moist with it, and the platinum point of 
a suitable anodal electrode placed in contact with it. 
The cathodal electrode, covered with sponge and moist- 
ened with the sodium chloride solution, may be held in 
the hand or applied to the side of the face or neck, and 
the current turned on, the same precautions being taken 
as when treating hypersensitive dentin. 

Short circuiting of the current is liable to occur 
if great care is not taken to keep the external sur- 
faces of the tooth dry. 

Some operators apply the cathode to the external surface of the tooth, 
and claim that more rapid effects are obtained on account of the shorter 
distance which the current has to travel. There is, however, considerable 




Syringe electrode. 



BLEACHING DISCOLORED TEETH. 



457 



danger of short-circuiting the current if the external surface of the tooth 
should become moistened, or by a movement of the patient the electrodes 
should accidentally come in contact with each other. 

The Hollingsworth syringe electrode (Fig. 565) may be used to keep the 
cotton moist with the bleaching fluid. 

To successfully employ the aqueous solution of hydrogen dioxide with 
the electric current, it is necessary to use a device which will permit the 
whole crown of the tooth to be enveloped in the bleaching fluid. 

Such a device has been invented by Dr. Hollingsworth, and described 
by him as follows : ' ' The bleaching electrode consists of a curved glass 
tube, with a metal top at one end, connecting with a spiral platinum wire 
in the tube (Fig. 566) and a rubber nipple (a) at the other end to enclose 
the tooth to be bleached. A metal cap plug (b) prevents the bleaching 
fluid from escaping, and the tip is provided with a groove for the at- 
tachment of the connecting cord. The appliance is held in place by the 
hooks attached to the metal tip of the tube, which are caught over the top 
of the rubber dam. 

"The duplex syringe (Fig. 567) is for the purpose of filling the tube 
and nipple with the bleaching fluid. The nozzle connects only with the rear 
Fig. 566. 

| 

Fig. 567. 




Bleaching electrode. 




Duplex syrinx 



bulb. When this is charged with the bleaching fluid the nozzle is inserted 
in the tube of the bleaching electrode, first compressing the forward bulb 
and allowing it to expand to exhaust the air in the tube and nipple, when 
pressure upon the rear bulb forces the bleaching fluid into the electrode. 

"The nipple-expander (Fig. 568) is for adjusting the rubber nipple to 
the tooth that is to be bleached. The closed end of the nipple is first 
perforated with the rubber-dam punch, and when placed upon the tooth 
and ligated forms a close-fitting and tight holder for the bleaching fluid." 

Before adjusting the bleaching electrode, the tooth should be prepared 
as for bleaching by any of the methods already described ; the pulp-canal 
and the tooth-cavity are then loosely packed with cotton previously satu- 
rated with the bleaching fluid. The object of this is to form a conductor 



458 



OPERATIVE DENTISTRY. 



that will carry the fluid to the remote recesses of the cavity and canal, and 
also to exclude air-bubbles which would act as insulators of the electric 
current. 

Fig. 568. 




Nipple-expander. 

The first step in the adjustment of the electrode is the placing of the rubber 
nipple in position by means of the nipple-expander (Fig. 568) and securing 
it firmly by a ligature passed around it at the cervix of the tooth, varnish 
or chlora-percha to be flowed over it as an added precaution against leakage. 

The free end of the nipple is now forced over the shouldered end of 
the glass tube and the hooks adjusted to hold the opposite end of the tube 
in position. The tube is now to be filled with the bleaching fluid by in- 
serting the nozzle of the duplex syringe — which has been previously 
charged — into the metal tip of the tube, compressing the forward bulb to 
exhaust the air. If air finds its way into the tube at the cervix of the 
tooth beneath the margins of the rubber nipple, varnish may be again ap- 
plied, and suction will draw it into and fill any little interstices which 
might give access to air. The rear bulb is compressed and the tube filled 
with the bleaching fluids, thus submerging and surrounding the crown of 

the tooth in the fluid. The 
Fig. 569. ., . -, 

positive pole is now con- 
nected with the metal end of 
the tube and the negative 
pole with the hand electrode, 
and these with the source of 
the current. 

Fig. 569 shows the bleach- 
ing electrode in position and 
connected with the positive 
pole. 

The current should be 
turned on slowly and the 
milliampere-meter closely watched ; a leak in the current is indicated by 
the registration of a greater amperage than is usually employed in such 
operations, — viz., one-tenth to one-half a milliampere upon vital teeth, 
which is increased to one and sometimes one and one-half milliamperes in 
bleaching devitalized teeth. 




CHAPTEE XXVIII. 



DISEASES OF THE PERICEMENTUM. 



The pericementum or peridental membrane is often the seat of various 
diseased conditions, both nutritive and functional. Among these are 
several distinct forms of inflammation, all arising from different causes, 
some local in origin, others constitutional, and each requiring, according 
to their origin, a different line of treatment for their cure. 

Bodecker classifies the diseases of the pericementum under two heads, 
- — viz., purulent and non-purulent. Burchard thinks this is misleading, as 
cases may be due to septic causes without pus-formation, while pus-forma- 
tion represents but one form of sepsis. Burchard * classifies them as septic 
and non-septic. 

Black f classifies the disorders of the pericementum under three heads : 
first, diseases which begin at the apex of the root ; second, those which 
begin at the border of the gingivae ; third, those beginning at some inter- 
mediate portion of the membrane. These are again divided into septic 
and non- septic, general and localized, acute and chronic. 

PERICEMENTITIS. 

Definition. — Pericementitis (from the Greek nepi, around; Latin, 
ccementum, cement ; Greek, trts, itis, the ending, signifying inflammation), 
inflammation of the pericementum or peridental membrane and the tissues 
immediately surrounding the tooth. 

Inflammation of the investing membrane of the roots of the teeth is 
therefore termed pericementitis, periodontitis, or dental periostitis. 

Xext to hypersemia and inflammation of the pulp, pericementitis is the 
most prolific cause of toothache. It therefore calls for a careful study of 
its pathology and its symptoms, that it may with certainty be differen- 
tiated from other affections which cause odontalgia. 

Causes. — Pericementitis may be divided into two distinct forms, one 
dependent upon local causes for its existence, the other upon general or 
constitutional conditions, and these forms may be either acute or chronic, 
septic or non-septic, in their character. 

Local pericementitis is a condition of inflammation of the investing root 
membrane caused by traumatic injury or septic poisoning. 

Traumatic pericementitis may be induced in vital teeth by blows, falls, or 
malocclusion, either from the natural movement of the teeth incident to 
the loss of supporting neighbors or by fillings which have not been prop- 



* Dental Pathology, Therapeutics, and Pharmacology, 
t American System of Dentistry, vol. i. p. 921. 

459 



460 



OPERATIVE DENTISTRY. 



Fig. 570. 



Fig. 571. 



erly shaped to give a perfect occlusion with opposing teeth ; by the press- 
ure of an ill-fitting partial set of artificial teeth ; by an ill-fitting crown or 
by an improperly adjusted clasp ; by excessive malleting and 
wedging ; by ligatures and rubber- dam clamps ; by the rapid 
movement of teeth in the operation of regulating ; by the pres- 
ence of a rubber band used in regulating, and which has been 
allowed to cut its way towards the apex, as shown in Fig. 
570 ; by the irritating presence of salivary calculus upon the 
roots ; by an imperfect root-filling, or by puncturing the side 
of the root with drills or reamers. 
In traumatic pericementitis the inflammatory condition is of an acute 
diffused character, seemingly involving the whole of the membrane at the 
same time, but presenting symptoms which, as a rule, are much less severe 
in their manifestations than those associated with septic conditions. In a 
majority of cases of traumatic pericementitis the inflammatory symptoms 
never reach the stage of suppuration and involvement of surrounding tis- 
sues. In the severer forms of injury, such as blows and falls upon the 
teeth, accompanied by laceration of the overlying tissues or partial luxa- 
tion of the teeth, induration and swelling are often very considerable, 
sometimes ending in suppuration from infection of the injured tissues. 
Perforation of the lateral wall of the canal often establishes a pericemen- 
titis which resists all efforts at treat- 
ment. Injuries, however, which do 
not cause a break in the continuity of 
the tissues do not, as a rule, suppurate 
unless the pyogenic organisms are al- 
ready in the system and are deposited 
at the point of injury from the blood- 
current. Under such circumstances the 
injured tissues, by reason of their low- 
ered vital powers of resistance, would 
furnish a favorable soil for the growth 
and propagation of the pyogenic organ- 
isms, and the formation of pus would be 
the result. 

Septic pericementitis may be either 
acute or chronic, and is usually the sequel 
of inflammation and gangrene of the 
pulp, the exceptions being such cases 
as those just mentioned. Septic peri- 
cementitis always begins as a circum- 
scribed inflammation, located at the apex 
of the root of the tooth, occasionally in- 
volving one or more teeth upon either 
side of it ; the tissues first involved are those of the apical space, and for 
this reason it is often spoken of and described as apical pericementitis. 

Acute apical pericementitis sometimes accompanies pulpitis ; when this 
dual condition is manifest in double- or multiple-rooted teeth, it is possi- 




A, dental pulp and its artery ; B, dentin ; C, 
tunica propria ; D, enamel ; E, pericementum ; 
F, cementum ; 6, canal in lower jaw ; H, dental 
artery ; J, branch of dental artery supplying 
pericementum ; K, branch of dental artery 
supplying tunica propria. (After Black.) 



DISEASES OF THE PERICEMENTUM. 461 

ble for oue of the roots to contain a devitalized pulp while the other por- 
tions are vital ; but when this dual condition occurs in teeth having a single 
root, another explanation is needed to account for the phenomenon. It 
seems probable, therefore, that inasmuch as the vessels of both the pulp 
and the pericementum arise from a common branch located at the apical 
space (Fig. 571), and the connective tissue which enters the foramen with 
the vessels and nerve-trunk is continuous with the pericementum at the 
apical space, the inflammation has spread by continuity of structure. 

Acute apical pericementitis, however, is not always of septic origin, 
for it may be the result of chemic irritation from the escharotic action of 
arsenous acid, zinc chloride, carbolic acid, or other irritating agents which 
have been applied to the pulp or to the canal and have escaped into the 
apical space. Or it may be due to the mechanic irritation of portions of 
filling-material which project beyond the foramen and press upon the 
apical tissues. 

Pathology. — Acute apical pericementitis due to septic infection from 
a gangrenous pulp does not differ materially in the pathologic changes 
which take place in its tissues from those which are observed in any other 
tissue which may be the seat of a septic inflammation. 

Irritation at the apex is produced by infection of the apical tissues with 
the micro-organisms of suppuration or of their waste products, or with the 
ptomaines of decomposition produced by the action of the saprophytic 
organisms upon the gangrenous pulp. At the beginning the irritation 
produces hyperseniia of the vessels of the pericementum, especially near 
the apex of the root ; this is followed by exudation of the liquor sanguinis 
and the migration of white blood- corpuscles, and later by proliferation of 
the connective-tissue cells. The pericementum now becomes thickened, 
and presents areas of cloudiness. Later as the inflammation progresses 
this cloudiness may extend over the entire surface of the membrane. 

At this stage, if the cause of the irritation is removed, resolution takes 
place and the tissues return to their normal state. Failing in this, the 
inflammatory process progresses, and the morphologic elements surround- 
ing the inflamed part — the leucocytes and the embryonic cells formed 
from the fixed tissue-cells — lose their vitality and are converted into pus- 
corjmscles, and through the digestive and peptonizing action exerted by 
the pyogenic organisms upon the intercellular substance of the tissues it 
is liquefied and pus is formed, resulting in dento-alveolar abscess. Occa- 
sionally the inflammatory process is confined to the apex ; at others it 
becomes diffused over the entire membrane. 

Symptoms and Diagnosis. — The first symptom noticed in acute 
pericementitis of septic origin is a gnawing, uneasy feeling of tension in 
and about the tooth, with a desire to bite upon it. This feeling of tension 
is produced by the hypersemic condition of the blood-vessels of the peri- 
dental membrane, and is relieved for the time being by forcibly biting 
upon the tooth. Forcible pressure upon the teeth drives the blood out of 
the vessels and relieves the tension for a few minutes, but the gnawing 
feeling and tension again return in a slightly increased form. Lateral per- 
cussion of the tooth reveals slight tenderness. The tooth now begins to 



462 OPERATIVE DENTISTRY. 

feel longer than the others, as though it were raised from the alveolus, and 
is slightly loose. This is actually the fact, for as the congestion of the 
blood-vessels goes on the membrane becomes thickened and the tooth is 
slightly raised from its alveolus. The gum around the tooth becomes 
swollen and tender, and the free margins assume a red or purple hue. 
Pain of a deep, dull, constant character will now be present. Lateral per- 
cussion is painful, and forcibly biting upon the tooth, instead of giving 
relief, now causes intense pain. The swelling slowly increases and the pain 
is still deep-seated, but gradually changing to a dull, throbbing character, 
while the tooth grows more and more sensitive to percussion. 

The swelling now becomes more defined and palpation will discover a 
softening at some one point with fluctuation, which indicates the forma- 
tion of pus, the penetration of the bone, and an early sjjontaneous evacua- 
tion of the pus by natural pointing, or it may escape by burrowing along 
the side of the root, finding an exit at the margin of the gum. The in- 
tensity of the symptoms will depend somewhat upon the character of the 
infection and upon the diathesis of the patient. 

Differential Diagnosis. — It has already been stated that pericemen- 
titis, next to pulpitis, was the most common cause of toothache. It there- 
fore becomes important to be able to make a diagnosis between them. At- 
tention has also been called to the fact that pulpitis and pericementitis may 
occasionally exist at the same time in an individual tooth having more 
than one root, but it is not impossible for this dual condition of inflamma- 
tion to exist in a tooth with a single root. Under such circumstances the 
sharp, stinging, lancinating pain of a pulpitis may be present and asso- 
ciated with soreness to percussion and elevation of the tooth in the 
alveolus. 

In a large majority of cases, however, pericementitis is not developed 
until after the vitality of the pulp has been destroyed and the saprophytic 
germs have begun their work of reducing the gangrenous pulp to its 
original elements. 

The pain from pulpitis is of a sharp, stinging character, and inclined to 
be paroxysmal and reflected to various parts of the face, making it often 
difficult to locate the tooth which is causing the pain. The normal heat 
sense is also greatly lowered, so that temperatures which can be borne by a 
healthy tooth become intolerable in one affected with pulpitis. While in 
pericementitis the pain is always located in the affected tooth, and is of a 
dull, heavy, gnawing character. The heat sense in pericementitis is raised 
somewhat above that of the tooth affected with pulpitis. In the early 
stages of an inflammation cold is soothing, as it contracts the blood-vessels 
and retards the progress of hyperseraia and exudation ; while in the stage 
of congestion and partial stasis heat is more beneficial, as it tends to pro- 
mote the movement of the blood, particularly in the congested veins, and 
thus relieves the tension upon the hypersensitive nerve-fibres of the in- 
flamed tissues. A rigor and elevation of temperature indicate the forma- 
tion of pus. 

Prognosis. — The usual duration of acute septic apical pericementitis is 
from three days to two weeks. In a majority of these cases the inflamma- 



DISEASES OF THE PEEICEMENTUM. 



463 



tion ends in suppuration and the formation of a dento-alveolar abscess, occa- 
sionally they terminate in resolution, while in others the cell proliferation 
results in the formation of new cement- tissue, — hypercementosis. The 
latter condition is the result of a continuation of the irritation that de- 
veloped the acute attack, but which is of a milder type, assuming a sub- 
acute or chronic form. 

Local Treatment. — The local treatment of acute pericementitis of 
either the traumatic or septic form is, first, to remove the cause of the irri- 
tation if it still exists. This comprehends, in the traumatic variety, the 
relief of malocclusions, the discarding of ill-fitting plates or crowns and 
improperly adjusted clasps, the removal of salivary calculus, or of root- 
fillings which are causing pressure upon the apical space. In the septic 
variety it means the opening of the pulp-canal and the removal of its 
decomposing contents, either by chemic means — treatment with sodium 
dioxide solution — or by mechanic means, in the use of broaches, barbed 
cleansers, etc, exercising the greatest care not to allow the broach or 
Donaldson cleanser to pass the apical foramen or to force the septic 
material into the apical space. Frequent irrigation with antiseptic 

Fig. 572. 




Dunn capillary or drop syringe. 

solutions should accompany the process of cleansing the canals, followed 
by the application of hydrogen dioxide, either upon a pledget of cotton or 
by the aid of the Dunn syringe (Fig. 572). After the canals have been 
thoroughly cleansed, they should be dressed with one of the essential oils 
or Dr. Black's one- two-three mixture : 

B Oil of cinnamon, 1 part ; 

Carbolic acid, 2 parts ; 

Oil of wintergreen, 3 parts ; 
or, 

R Eugenol, 1 part ; 

Carbolic acid, 2 parts ; 

Eucalyptol, 3 parts ; 



or with some other suitable antiseptic. 

In opening the canals of teeth which are very sore the tooth should be 
supported with the thumb and index-finger of the left hand while drilling 
through the overlying dentinal tissue or the filling, as the case may be. 
Or a ligature may be tied around the cervix of the tooth, the ends being 
left long enough to extend well beyond the mouth, and traction made upon 
it, as suggested by Dr. J. Foster Flagg, to counteract the pressure of the 




464 OPERATIVE DENTISTRY. 

drill. The immediate opening of the canals is imperative in all cases 
where the pulp has died under a filling, otherwise the accumulation of the 
mephitic gases will force the septic material contained in the pulp-canal 
into the apical space and establish an acute alveolar abscess. Such teeth 
do better if left open for from twenty-four to forty-eight hours than they do 
if dressings are applied. If left open, the gases of decomposition readily 
escape, while if the opening is closed, they rapidly accumulate and keep 
up the irritation. 

Secondly, to secure rest for the tooth by preventing the opposing tooth 
from occluding with it. This may be done by moulding a piece of base 1 
plate gutta-percha to the crowns of the lower bicuspid and 
molar teeth upon the opposite side of the mouth, or the 
adjustment of a metal cap, as shown in Fig. 573, so that 
when the teeth are closed they rest upon the gutta-percha 
splint or the metal cap. Or, if there are no teeth remain- 
ing upon the opposite side, a tooth in front or behind the 
Metal cap. affected one may be utilized for the purpose. Or a hollow 

rubber crown, made by the S. S. "White Company, may be 
placed upon a tooth in a suitable location. A still more simple and ef- 
ficient method is to dry the morsal surface of two or three teeth upon the 
same side of the mouth, preferably the lower teeth, and cover them with 
zinc oxy phosphate cement. The writer prefers Ames's metaloid for this 
purpose to any other, on account of its great adhesive qualities. 

After rest has been secured, the third step in the treatment is the ex- 
hibition of topical remedies for the relief of the pain and controlling or 
aborting the inflammatory symptoms. The local congestion may be re- 
lieved by freely scarifying the gum over the affected tooth, and promoting 
the bleeding by the free use of warm water. Or counterirritation may be 
employed by painting the gum with cantharidal collodion or with the 
following combination of remedies : 

R Tincture of aconite, 
Tincture of iodine, 
Spirits of chloroform, 
Spirits of camphor, aa f g i. M. 

Darby's capsicum and sinapin dental plasters will also be found beneficial 
in deflecting the blood to the surface, if applied to the gum directly over 
the affected tooth. The hot- water bag applied to the side of the face is 
often very soothing in the more advanced stage of the inflammation. It 
should be wrapped in a towel or covered with several thicknesses of 
flannel, to conserve the heat and to furnish an agreeable surface upon 
which to rest the face. 

Constitutional Treatment. — The throbbing pain may often be 
greatly relieved by the use of a hot foot-bath to which a tablespoonful or 
two of mustard has been added. This equalizes the circulation by causing 
a determination of blood to the lower extremities, and relieves arterial 
tension in the upper part of the body, and by that process mitigates the 
pain. A brisk saline laxative is also beneficial in many cases. 



DISEASES OF THE PERICEMENTUM. 465 

In the more severe cases, accompanied with febrile symptoms, full, 
bounding pulse and high temperature, coated tongue, constipation, head- 
ache, and chilliness, efforts are still to be made to abort the inflammation. 
Quinine in doses of from five to ten grains may be administered, or some 
of the coal-tar derivatives, like phenacetine or antikamnia, may be em- 
ployed in five- to ten-grain doses until the excessive rapidity of the pulse 
is controlled and the pain rendered less severe. If the inflammatory 
symptoms are not markedly less by bedtime, ten to fifteen grains of 
Dover's powder may be administered with a hot lemonade or other hot 
drink, and the patient, after a hot foot-bath, placed in bed and covered 
with an extra blanket in order to promote copious diaphoresis. 

Or bromide of potassium, fifteen to twenty-five grains, combined with 
tincture of veratrum viride, five minims, may be administered, and repeated 
in four hours if needed. 

Constipation may be relieved by taking in the morning before 
breaking the fast a glass of Hunyadi water or one-half ounce of sulphate 
of magnesia in a glass of water, or a grain of calomel may be adminis- 
tered at bedtime, omitting the lemonade, and following it in the morning 
with a Seidlitz powder. 

Some operators have great faith in the constitutional effect of calcium 
sulphide in limiting the suppurative process. Its use is, however, some- 
what empirical, as there is no definite knowledge of its physiologic action 
upon the tissues. The theory has been advanced, and the results seem to 
prove the theory, that it has, first, a stimulating effect upon the blood- 
current and glandular elements of the mucous membrane and the skin ; 
secondly, this stimulating effect is noticed in the increased movement of the 
blood- current and in the amount of normal glandular secretions, while it 
checks that due to venous congestion and blood stasis ; thirdly, it is thought 
to produce H 2 S in the system, which has a controlling or restraining influ- 
ence upon the amseboid movements of the wandering cells or leucocytes. 

SUBACUTE AND CHRONIC PERICEMENTITIS. 

These conditions present all of the characteristics of the acute form of 
the disease, but in a less severe form. 

The most common cause of subacute and chronic pericementitis is a 
septic condition of the pulp-canals, sometimes resulting in pericemental 
soreness only, or in the formation of pus. These forms of pericementitis 
are usually the sequelse of acute attacks of the affection. They may also 
occur in teeth in which the pulps have been removed and the canals filled, 
but this condition is usually found associated with crooked roots or con- 
tractions of the caliber of the canals which have prevented the complete 
removal of the pulp to the apical foramen ; or they may be caused by septic 
conditions from a pulp which has died under a filling ; and occasionally 
they are found associated with apparently sound teetb that have suffered 
from some traumatic injury which caused death of the pulp, but which for 
a long period gave no trouble ; or with teeth whose pulp vitality has been 
lost through the plugging of the artery of supply by a thrombus, and fatty 
degeneration has taken place in the tissues of the pulp. In a considerable 

30 



466 OPERATIVE DENTISTRY. 

number of cases of subacute and chronic pericementitis there is no evidence 
whatever of the formation of pus, or even of swelling of the overlying 
gum-tissue. This is true of even some of the septic cases. It would seem, 
therefore, from this that the character of the septic organisms was less 
virulent than during the acute attack, or that the tissues are more resistant 
to the action of the organisms or their waste products, or perhaps both of 
these suppositions are true, and for that reason the inflammatory process 
runs a less vigorous course. 

Symptoms. — In chronic apical pericementitis the patient usually 
complains of periodical soreness, which lasts for a day or two, or perhaps 
for three or four days ; the soreness then disappears to return again after 
a shorter or longer interval. In some of these cases the gum will be 
markedly congested, in others no discoverable change in the color of the 
gum takes place. Percussion is more or less painful, and palpation over 
the apex of the root often gives evidence of tenderness. The tooth is not 
sensitive to changes of temperature. 

Marked sensitiveness to changes of temperature would indicate hyper- 
sensitive dentin or inflammation of the pulp, and should exclude perice- 
mentitis from the diagnosis. Upon close examination of some of these 
cases a very slight discharge of pus may be discovered at the cervix of the 
tooth, and if a fine probe is passed into the opening from which the pus 
can be pressed, it will follow a sinus or open track which the pus has made 
for itself at the side of the root down to the apex. 

Treatment. — Many cases of chronic pericementitis are dependent for 
their origin upon traumatic injuries like malocclusions due to the natural 
movement of the teeth towards each other after a supporting neighbor has 
been lost. The malocclusion may be one in which the pressure upon the 
tooth is too great, or it may be in a wrong direction, forcing it into an 
abnormal position. The tooth is often slightly loose and sore to pressure 
or percussion. Or the malocclusion may be caused by a filling which has 
not been properly occluded to the morsal surface of the antagonizing tooth. 
In either case the tooth or the filling should be cut away until a natural or 
comfortable occlusion has been restored, when, by the aid of the local 
application of the aconite and iodine preparation to the gum over the apex 
of the tooth, the soreness and looseness will soon disappear. 

Devitalized teeth which have had their pulp-canals filled furnish a 
considerable number of mild septic cases which result in chronic perice- 
mentitis. This is due sometimes to imperfect sterilization of the dentin, or 
of fragments of pulp left in tortuous canals and crooked roots ; at others to 
imperfect methods of cleansing and filling the canals, or of forcing portions 
of the filling-material beyond the foramen. In all such cases the root- 
filling should be removed, and the operation of cleansing the canals, 
sterilization, and filling done over again, as this is the only way in which 
it is possible to secure restoration of health to the tooth. 

The difficulties are such sometimes, however, on account of the mal- 
formation of the roots, that it becomes impossible to completely sterilize 
the canals and restore the tooth to a healthy condition, even after repeated 
trials of resterilization and filling. Under such circumstances the extrac- 



DISEASES OF THE PERICEMENTUM. 467 

tion of the tootli is the only way out of the difficulty, and this is to be 
advised rather than to allow the tooth to remain as a constant source of 
irritation. 

GENERAL NON-SEPTIC PERICEMENTITIS. 

General or constitutional non-septic pericementitis is an inflammation 
of the pericementum involving a number of teeth at the same time in one 
or both jaws, and dependent upon certain specific systemic conditions, 
such as rheumatism and gout, tubercular conditions, scorbutus, diabetes 
mellitus, and albuminuria, or to the local toxic manifestations of certain 
drugs like mercury, iodine, and phosphorus, and the preparations of gold, 
copper, antimony, arsenic, etc. 

The pathologic changes which take place in non-septic pericementitis 
due to systemic conditions are in general the same as are found in those 
cases which are dependent upon local causes for their origin. But the 
exudations are much more liable to become organized into new tissue, re- 
sulting in hypercementosis. 

The tendency of acute local pericementitis is, from the severity of the 
inflammation, to produce death of the exuded leucocytes and the embryonic 
cells formed from the fixed tissue- cells— necrobiosis — and the formation 
of pus. While in certain forms of systemic or general pericementitis the 
tendency is strongly to the formation of new tissue, through the organization 
of the escaped leucocytes and the embryonic cells. This tendency is most 
often noticed in that form of pericementitis due to the specific action of 
gout and rheumatism. On the other hand, when the inflammation is due 
to certain other systemic conditions like tuberculosis, scorbutus, diabetes 
mellitus, albuminuria, and mercurial ptyalism, the tendency is in the 
direction of necrobiosis and the formation of pus. 

Rheumatic and gouty pericementitis is rarely general in its character. Its 
most frequent manifestations are decidedly local in the sense that only a 
few teeth are involved at the same time, although occasionally all of the 
teeth may be the seat of inflammatory symptoms due to these causes. 

Clinical and post-mortem experience teaches that the materies morbi of 
these diseases has a predilection for the fibrous structures of the body, 
especially the synovial membranes, the aponeuroses of muscles, the dura 
mater, the cardiac tissues, and the periosteal and pericemental membranes. 
The structure most commonly affected is the synovial membrane, resulting 
in inflammatory conditions of the joints. 

It not uncommonly happens, however, that there is associated with the 
inflammatory phenomena of the joints enlargements of the long bones and 
nodular formations in other localities, while conditions somewhat analogous 
are often presented in the pericementum. 

The predisposing and exciting causes of certain irritative conditions of 
the pericementum seem to have their origin in the same conditions which 
bring about the phenomenon of rheumatism and gout, and they have also 
proved by experience to be amenable, in many cases, to the same specific 
treatment adopted in these diseases. It is a notable fact, also, that in 
persons suffering from this form of pericementitis the urine, saliva, and 
perspiration nearly always give a decidedly acid reaction. Serumal de- 



468 OPERATIVE DENTISTRY, 

posits sometimes form upon the root of the tooth near the apex when there 
is no connection between the deposit and the mouth. Under such circum- 
stances suppuration often supervenes, and produces a form of pyorrhoea 
alveolaris. 

The pericementum seems to be very susceptible to the irritating effects 
of an acid condition of the blood, whether from an excess of lactic or 
uric acid retained in the system or from such acids as are found in sour 
wines and malt liquors. The habitual use of sour wines and malt liquors 
by those having the rheumatic and gouty diathesis greatly aggravates 
these conditions, and some individuals are so susceptible to their irritating 
influence that a slight indulgence will often precipitate an attack of acute 
articular rheumatism, of gout, or of pericementitis. 

General pericementitis of a mild form is often the forerunner of an 
acute attack of rheumatism or gout ; while, upon the other hand, a general 
or a local pericementitis, involving a number of teeth in different parts of 
the mouth, may be the only manifestation or expression of the presence of 
the rheumatic or gouty diathesis. 

Congestion and thickening of the pericementum and temporary loosen- 
ing of the teeth, and occasionally death of the pulp, accompanied by dull, 
gnawing pains and more or less soreness, are a not infrequent occurrence 
in attacks of rheumatism and gout. 

Symptoms and Diagnosis. — In rheumatic and gouty pericemen- 
titis soreness and pain in the teeth are early symptoms, and generally 
associated with an acid condition of the salivary secretions, of the perspi- 
ration, and of the urine ; while it is not at all uncommon to find the indi- 
vidual at the same time suffering from muscular pains which are unmis- 
takably rheumatic in character, or from an acute arthritis of one or more 
joints of the extremities. Sometimes, however, the only manifestations 
of the rheumatic and gouty conditions are the soreness and painful condi- 
tion of the teeth and the acid condition of the saliva and the urine. 

Rheumatic and gouty pericementitis, like rheumatism and gout in gen- 
eral, may be acute or chronic in their manifestations. The acute form is 
usually established as the result of taking cold or of over-indulgence in 
the pleasures of the table, and like those general conditions is greatly ag- 
gravated by bad weather, a low barometer, and excesses in eating and 
drinking. The chronic form of the disease is the result of repeated attacks 
of the acute form, and most often terminates in hypercementosis. 

• Soreness of the teeth to pressure, as in mastication, is the first symp- 
tom of acute rheumatic and gouty pericementitis. This condition is at first 
relieved by continued pressure, and the individual desires to close the 
teeth together and keep them in this position. After a few hours the teeth 
become painful to such pressure, and constant effort is made to prevent 
the teeth from coming forcibly in contact. Mastication then becomes very 
painful or impossible, and liquid food only can be taken. The gums be- 
come more or less congested and purplish in color, but suppuration rarely 
takes place except where concretions have been formed upon the roots. When 
the disease is confined to a few teeth in a single location or iu different 
parts of the mouth, they have the feeling of being loose and considerably 



DISEASES OF THE PERICEMENTUM. 469 

elongated. This is due to the congestion and thickening of the perice- 
mentum, which lifts the teeth from their alveoli and makes them loose. 

Differential Diagnosis. — Difficulty is sometimes experienced in diag- 
nosing between a rheumatic or gouty pericementitis and an incipient or 
chronic apical pericementitis due to septic conditions. These difficulties 
arise from the fact that pulpless teeth are much more liable to become the 
seat of rheumatic symptoms than normal teeth, consequently, when several 
devitalized teeth become the seat of pericementitis, it is almost impossible 
in the early stage to diagnosticate between them except by inference. The 
fact, however, remains that in a rheumatic pericementitis several teeth are 
almost invariably affected at the same time, while in septic apical perice- 
mentitis a single tooth is usually at fault. Should three or four devitalized 
teeth be in a state of septic apical inflammation at the same time, the diag- 
nosis could be proved by the absence of the other symptoms which usually 
accompany an attack of rheumatic pericementitis. The duration of the 
symptoms will vary from three or four days to as many weeks, depending upon 
the severity of the attack and the success of the constitutional treatment. 

Prognosis. — The prognosis in this form of pericementitis is generally 
good, for the reason that the acute symptoms are usually controlled by 
systemic treatment. In the chronic form of the disease the prognosis is 
less favorable, as hypercementosis is the usual sequel, and systemic treat- 
ment has little or no effect upon the progress of new-tissue formation. 

Treatment. — The treatment of these forms of pericementitis is largely 
systemic, and is comprehended in the regular methods employed in general 
rheumatic and gouty conditions, — viz., the exhibition of such remedies or 
combination of remedies as have for their base salicylic acid or colchicum, 
or both, mercurial and iodine compounds, lithia, various mineral waters, 
hot mineral baths, and Turkish baths. A restricted diet which reduces 
the quantity of meat consumed and cuts off all game, wine, and malt 
liquors, is also beneficial. 

Local treatment in the form of depletion to directly relieve the con- 
gested condition of the gums, and indirectly of the pericementum, often 
gives relief after a little time. This may be obtained by scarifying the 
gums and promoting bleeding by the use of tepid water held in the mouth. 
Or these symptoms may be relieved by counter-irritation, as already de- 
scribed upon a preceding page. If suppuration be present, the pockets 
should be explored for calcic deposits, and if discovered, they should be 
removed and the pockets treated with dilute sulphuric acid, trichloracetic 
acid, or other stimulating and antiseptic applications. For further 
methods of treatment of this form of the disease the reader is referred to 
the chapter on "Pyorrhoea Alveolaris." 

TUBERCULAR PERICEMENTITIS. 

Pericementitis occurring in an individual of tubercular diathesis runs 
such a peculiar and rapid course that it deserves separate mention. Al- 
though, strictly speaking, the term as above applied may not be, perhaps, 
correctly used, it nevertheless serves to describe a condition by no means 
uncommon, and which sometimes has serious consequences. 



470 OPERATIVE DENTISTRY. 

Iii using this term it is not intended to imply that the form of peri- 
cementitis to be described is due to the presence of, or originates in, the 
tuberculous condition, or that the tubercle bacilli are the cause of the 
peculiar and rapid course of the disease. 

In all of the cases which have come under the observation of the writer, 
the primary cause of the affection was a traumatic injury of the pericemen- 
tum, produced by either excessive malleting, as in large contouring opera- 
tions, the rapid movement of the teeth, or a malocclusion. In all of the cases 
the patient gave unmistakable evidences of having a tuberculous diathesis. 
It is generally conceded to be a clinical fact that injuries occurring in 
tubercular subjects are much more prone to end in suppuration than are 
like injuries in other persons, and that the inflammatory process is much 
more acute than in other individuals. 

The following case, which is introduced by way of illustration, occurred 
in the practice of the writer. The patient was a college student for whom 
he had made two large countour fillings with gold in approximating cavi- 
ties in the right superior bicuspids. The operations had consumed four 
hours of time in the preparation of the cavities and inserting and finish- 
ing the fillings. The teeth were vital, and the hand-mallet was used in 
condensing the gold. In a few hours after the operation the teeth became 
very sore and painful, and at the end of twenty-four hours the face was 
greatly swollen and the gums tumefied, soft, and boggy from the lateral in- 
cisor of the right side back to and including the second molar. The teeth 
thus involved were all loose and exceedingly sensitive to pressure or percus- 
sion. On lancing the gums, which was done in several places, thick creamy 
pus was discharged in great cpaantity, and upon irrigating the jms-cavity it 
was found to be continuous through the whole extent of the inflamed area. 
The periosteum was also lifted from the external plate of the alveolar pro- 
cess, but higher up over the bicuspids than the other teeth. The abscess 
continued to discharge for several weeks, but finally closed without necrosis 
of the bone. The teeth all became firm in their alveoli and remained vital. 

Other cases of a similar nature occurring from various injuries in which 
necrosis of the external alveolar plate resulted from the inflammation 
might be described, but this is sufficient for the purpose of illustration. 

SCORBUTIC PERICEMENTITIS. 

This form of pericementitis is one of the marked symptoms of scurvy. 
It is the result of long exposure to a cold and damp atmosphere, coarse 
diet, insufficient vegetable food, and fatiguing labor. It most frequently 
occurs among sailors of the Arctic regions, particularly whalers. It is 
also seen among soldiers and the men of lumber camps. It is not infre- 
cpiently seen in our large cities among the very poor, who are housed in 
damp basements and cellars, and whose food-supply is very scanty and of 
the least nutritious varieties. 

Occasionally little children under two years of age are victims of the 
disease, and this is an evidence of malnutrition. 

Symptoms and Diagnosis. — Scorbutic pericementitis, as a rule, 
attacks all of the teeth in rapid succession, and is therefore a general 



DISEASES OF THE PERICEMENTUM. 471 

pericementitis. In a typical case of scurvy the teeth are all loose, sore, 
and painful, making mastication impossible. The gums are swollen and 
spongy, purplish in color, and bleed easily, while pus exudes around their 
margins and from the dental alveoli. The breath is fetid and sometimes 
there is an increased flow of saliva. Associated with the oral symptoms 
there are certain manifestations of the disease upon the skin in the form 
of livid spots intermixed with spots of a less vivid color. These spots are 
small and resemble flea-bites. They sometimes occur in patches or in 
strips and are usually located at the roots of the hair ; they are scattered 
over the chest, thighs, arms, and trunk, and are occasionally seen upon the 
mucous membrane of the mouth and nasal passages. The disease is ac- 
companied by extreme weakness, general debility, and depression of 
spirits. Occasionally there is severe pain in the extremities, particularly 
in the wrists and ankles. In the severer form of the disease, hemor- 
rhage occurs from the livid spots found upon the skin {purpura hcemor- 
rhagica), and from the spots found upon the mucous membrane of the 
mouth and nose. In many of these cases there is a considerable deposit 
of salivary calculus about the cervices of the teeth. 

Treatment. — The treatment of scurvy calls for a radical change in the 
sanitary surroundings of the patient. A generous diet, supplemented 
with green vegetables and acid fruits, is generally all that is required in 
the way of general treatment. In the severer cases tonics are called for, 
like the elixir of calisaya, strychnine and iron, or quinine. 

The local treatment for the inflammatory conditions of the teeth and 
gums would be to cleanse the mouth by the use of hydrogen dioxide, re- 
move all deposits of soft debris and salivary calculus from the teeth, relieve 
the congestion of the gums by painting them with the tincture of aconite 
and iodine, equal parts, or by scarifying them with a sharp lancet, and 
prescribing an antiseptic and astringent mouth lotion. In indolent and 
ulcerative conditions the gums may be painted with a ten per cent, solu- 
tion of zinc chloride in water. 

General pericementitis is often a progressive symptom in diabetes mel- 
litus, BrighVs disease, and locomotor ataxia. The conditions which are pre- 
sented are similar to those which will be described later under the head of 
pyorrhoea alveolaris, with the exception that the roots of the teeth when 
finally exuviated do not usually show any signs of serumal deposits. 

MERCURIAL PERICEMENTITIS. 

This form of the disease is due to the constitutional impression of 
mercury. Mercurial ptyalism with its attendant evils has been so common 
in the past that almost every practitioner of twenty-five years' experience 
saw many cases in the early days of his practice. But happily in these 
later years the use of the drug has been greatly restricted, so that at the 
present time such cases are rarely seen except in the Southern States. 

The effects which are produced by mercury upon the general system, 
and locally in the mouth, depend upon th,e quantity administered and the 
susceptibility of the individual to the action of the drug. Children be- 
tween the ages of five and ten years are peculiarly susceptible. There is, 



472 OPERATIVE DENTISTRY. 

however, a very great difference in the susceptibility of various individ- 
uals ; in one an ordinary dose of blue pill or of calomel will produce a severe 
general pericementitis, inflamed gums, profuse salivation, and swollen 
tongue, while another seems to be almost proof against its action, even in 
large and repeated doses. 

Garretson records a case of mercurial poisoning in a child seven years 
of age in which the administration of three grains of calomel resulted in 
the loss by necrosis of the left half of the lower jaw. 

The writer has recorded a case * of a woman thirty years of age in 
which fifteen grains of calomel taken in three-grain doses at bedtime pro- 
duced necrosis of both jaws, accompanied by extensive sloughing of the 
gums of the inferior maxilla and of the soft tissues covering the roof of 
the mouth, swollen tongue, intolerable fetid breath, excessive salivary se- 
cretion, loosened teeth, and an uncontrollable diarrhoea, the case ending in 
death from exhaustion. 

Various other drugs, such as potassium iodide, pilocarpin, the prepara- 
tions of gold, copper, antimony, arsenic, etc., are capable of producing 
ptyalism ; and if this condition is maintained for any considerable period, 
the pericementum becomes involved, resulting in inflammation of this 
membrane, suppuration, and possible loss of the teeth. 

All of these drugs are in some degree eliminated from the system by 
the salivary glands, and during their elimination they seem to perform the 
functions of active irritants. A moderate degree of salivation may cause 
a considerable amount of soreness and tenderness about the gums and the 
roots of the teeth, but this soon subsides, and no permanent injury has been 
wrought. But if this condition is repeatedly induced or maintained for a 
considerable period, pathologic changes are established in the pericemen- 
tum, which permanently injure the organs of mastication and hasten their 
destruction. 

Symptoms and Diagnosis. — Pericementitis due to the toxic effect of 
mercury upon the general system usually involves all of the teeth. The 
condition generally begins with an increased flow of saliva and a metallic 
taste in the mouth. Later pericemental irritation is developed, followed 
by thickening of the membrane and extrusion of the teeth, which be- 
come loose and painful. Pus is formed in the alveoli and discharged at 
the margins of the gums. The gums become inflamed, swollen, and tur- 
gid, and bleed upon the least provocation. The breath is offensive, and the 
saliva, which is mixed with pus and blood, has the odor of decomposing 
animal matter. The tongue is swollen and often fills the mouth, pressing 
upon the teeth, which leave their imprint upon its edges. The secre- 
tion of the saliva is so great that it constantly drips from the mouth, and 
in the severer cases the amount may reach several pints in twenty-four 
hours. The salivary glands, as a result of their excessive secretion of 
saliva, frequently become swollen and painful. Diarrhoea is often a promi- 
nent symptom. 

The excessive flow of saliva distinguishes this form of ptyalism from 

* Injuries and Surgical Diseases of the Face, Mouth, and Jaws, p. 272. 



DISEASES OF THE PERICEMENTUM. 473 

all others, and although it were impossible to obtain a direct history of the 
administration of mercury, this particular symptom alone would strongly 
indicate the nature of the affection. 

Prognosis. — The prognosis in the milder form of the affection is favor- 
able to a complete recovery of the tissues to a normal condition. In the 
severer cases the teeth are not only endangered, but the gums, alveolar 
processes, and even the jaws may be seriously affected. Gangrene and 
sloughing of the gums, necrosis of the alveolar processes, and loss of the 
teeth are common sequelae, and, as already indicated, necrosis of the body 
of the jaw may sometimes be added to the category of evil results which 
have followed the administration of even small doses of mercury. Fibrous 
or cicatricial anchylosis of the jaws sometimes follows as a result of slough- 
ing of the gums and mucous membrane of the cheeks, which upon healing 
bind the jaws together with cicatricial bands. 

Treatment. — The treatment of this form of pericementitis must be 
directed to the systemic condition ; the first step being to cut off the ad- 
ministration of the drug and hasten its elimination from the system. This 
may be accomplished by means of potassium iodide, purgative mineral 
waters, diuretics, and diaphoretics. The diet should be generous and com- 
posed of the most nutritious food. The local conditions may be treated 
with solutions of potassium chlorate, silver nitrate or hydrochloric acid, 
and astringent deodorant mouth- washes. Especial care should be given to 
the cleanliness of the mouth. Hydrogen dioxide will be found a most 
efficient remedy for this purpose sprayed into the mouth and between the 
teeth. 



CHAPTER XXIX. 

DENTO-ALVEOLAK ABSCESS. 

Definition. — Abscess, from the Latin abscedere,to depart. 

An abscess is an accumulation of pus in the tissues of the body, re- 
sulting from a localized inflammation, and which is surrounded by a wall 
of lymph (formerly termed the pyogenic membrane, from the erroneous 
notion that it secreted pus). An abscess may also be termed a hollow 
ulcer. 

A dento-alveolar abscess is an accumulation of pus within a dental alveo- 
lus, or associated therewith, and dependent upon a septic inflammation 
of the tissues of the apical space or the pericementum, the former re- 
sulting from a gangrenous pulp, the latter from various forms of irritation 
or injuries resulting in suppurative inflammation. 

Causes. — Suppurative inflammation always precedes the formation of 
an abscess, and the presence of pyogenic bacteria is necessary to establish 
a suppurative inflammation ; hence it may be stated that an abscess is the 
result of the infection of the tissues with the pyogenic micro-organisms 
which produce the destruction of the exuded leucocytes and the cellular 
elements of the tissues at the point of infection, and the liquefaction of 
the intercellular substance, thus forming pus. 

It is possible, however, to produce pus without the agency of micro- 
organisms, as, for instance, by the injection of croton oil and other violent 
irritants beneath the skin ; but the pus so formed is aseptic, and if 
other animals are inoculated with it, it does not produce inflammatory 
symptoms, while a septic pus produced by the action of the pyogenic or- 
ganism will invariably cause suppurative inflammation if a sufficient 
quantity is introduced into the tissues. 

Exciting Causes. — The exciting causes of dento-alveolar abscess are 
found in septic conditions resulting from the death of the pulp and from 
certain inflammatory affections of the pericementum considered in the 
preceding chapter. 

The most common exciting causes of dento-alveolar abscess are the 
organisms of suppuration and of decomposition, — viz., the pyogenic and 
saprophytic bacteria. These organisms are constantly found in the mouths 
of even the most cleanly persons, and are an ever-present menace to all 
operations upon soft tissues which break the continuity of their surface, 
and the pulps of teeth which have been exposed by caries or by surgical 
traumatism. 

The ptomaines or waste products of these organisms, and the mephitic 
gases formed (hydrogen sulphide, H 2 S) as the result of the decomposition 
of the tissues of the pulp, passing through the apical foramen and coming 
in contact with the tissues of the apical space, cause irritation and a 
lowered vitality of the tissues as a result of their poisonous effect. The 
.474 



DENTO -ALVEOLAR ABSCESS. 475 

inflammation which follows, however, is not always of the same character 
or intensity, the difference in these respects being controlled, seemingly, 
by certain predisposing causes, — viz., the virulence of the organisms, the 
local resistance or stamina of the tissues, and the general condition of the 
individual. 

Predisposing Causes. — The character of a septic inflammation de- 
pends in great measure upon the virulence of the organisms which have 
been introduced into the system. This is a well-established law in both 
pathology and animal toxin therapy, and has been abundantly demon- 
strated by experiments upon animals and upon man, as, for instance, in 
the treatment of anthrax with the attenuated virus, and of malignant 
inoperable sarcomas with the toxins of the bacillus prodigiosus and with the 
streptococcus erysipelatus. 

The effect of an infection with the pyogenic cocci will always vary 
with the number of the organisms which have entered the tissues. Watson 
Cheyne found in his experiments with the proteus vulgaris of Hauser — a 
bacterium commonly associated with putrefaction — that a dose of one- 
tenth cubic centimetre of an undiluted culture contained about two hun- 
dred and fifty million bacteria, and when injected into the muscular tissue 
of a rabbit quickly proved fatal ; while a dose of one-fortieth cubic centi- 
metre, containing about fifty-six million, caused very extensive abscesses, 
and resulted in death of the animal in from six to eight weeks. Doses 
which contained less than eighteen million very rarely produced any effect. 
These experiments demonstrated the fact that the system when in a healthy 
condition has wonderful resistive power against the organisms of disease. 

He further demonstrated with cultures of the staphylococcus pyogenes 
aureus that it was necessary to inject a dose sufficient to include at least 
one billion cocci into the muscle of a rabbit to produce a speedy fatal 
result, while a dose containing two hundred and fifty million caused the 
formation only of a small circumscribed abscess. 

The staphylococcus pyogenes albus produced the same results, but required 
somewhat larger doses. 

Another fact of great interest was discovered by this investigator, — viz., 
that concentration of the septic material in a certain locality was necessary 
to produce the most marked results. Dividing the dose and injecting it at 
different times, or in different localities at the same time, did not produce 
the same results as when it was all injected into a single locality. 

The tone, resistance, or stamina of the tissues play an important part 
in the predisposition to infection. Tissues whose vitality or resistive 
powers have been lowered by traumatism, either accidental or surgical, or 
by disease, succumb more readily to a septic infection than do tissues in a 
normal condition. Healthy protoplasm is possessed of great resistive 
power to the action of disease-producing bacteria, and this is the salvation 
of the human race. But for this every member of the human family 
would become diseased, and the race soon swept from the face of the earth. 

The general condition or tone of the individual is an important factor 
in the predisposition to infection. Persons who are debilitated from illness, 
overwork, anxiety, debauchery, and other causes are far more susceptible 



476 OPERATIVE DENTISTRY. 

to the invasion of pathogenic organisms than are those in robust health. 
The same is true of individuals who have inherited syphilis and that con- 
dition generally known as struma. In these cases the evidence of a lack 
of vital resistive power is often strongly marked, and when children pos- 
sessing these diatheses are attacked by disease, they more readily succumb 
than do those children born of healthy parents. In this class of individ- 
uals all inflammatory conditions of the tissues of the mouth and the teeth 
run a violent course, and suppurative conditions which involve the perice- 
mentum, the periosteum, the alveolar processes, or the body of the jaw are 
prone to result in phlegmonous conditions of the soft tissues, involvement 
of the lymphatic glands, and not infrequently in septic intoxication. 

Certain acquired cachexia} like syphilis and tuberculosis also predispose 
the individual to a more virulent manifestation of a septic inflammation 
than in persons of good constitution, for the reason that these diseases 
markedly lower the power of resistance of the tissues and decrease the 
phagocytic power of the leucocytes. These predispositions are most pro- 
nounced in early life, and, as a rule, grow less and less prominent with 
the advancement of age ; but sometimes they persist throughout the whole 
lifetime of the subject. 

Varieties. — Dento-alveolar abscess presents in two forms, — viz., acute 
and chronic. In the acute form the symptoms are often very severe and 
sometimes alarming, resulting in extensive necrosis of bone, gangrene and 
sloughing of soft tissues, acute septicaemia, pyaemia, and death. In the 
chronic form of the disease the symptoms are of a much milder type, but 
necrosis of bone, septicaemia, and pyaemia are not unheard-of conditions 
in connection with chronic alveolar abscess. 

Dento-alveolar abscess is sometimes described as open or patulous, and 

blind. An open or patulous abscess is one which has a fistula through the 

gum or other location, from which the accumulated pus discharges. A 

blind abscess is one which has no opening, except the pulp- 

574. oana i 7 through which the pus could escape. Blind abscesses 

are usually of the chronic or subacute variety. 

Pathology. — When the pyogenic bacteria gain an entrance 
to the tissues of a living body they accumulate very rapidly, 
forming a minute colony which by their concentrated action, or 
that of their chemic product, causes coagulation of the serum 
and of the contiguous tissue, — "coagulation necrosis," — thus 
forming a nidus or central point for the development of the 
process of suppuration. Around this central point, composed 
of necrotic tissue and containing a colony of micro-organisms, 
or lymph-waii the leucocytes accumulate in great numbers, completely en- 
of tooth ab- closing it by forming a wall of lymph, as shown in Pig. 574 

scess as met & J ° . 

withindento- (the pyogenic membrane of the older writers), 
alveolar ab- According to the theory of Metchnikoff, certain cells, known 

as phagocytes, play an important part in limiting the action of 
the bacteria. The phagocytes are of two varieties, fixed and free. The 
fixed phagocytes are the endothelial cells and the fixed connective- tissue 
cells, while the free phagocytes are the wandering cells or leucocytes. It is 



DENTO ALVEOLAR ABSCESS. 477 

claimed that the phagocytes attack the micro-organisms which are found 
in the tissues and destroy them. These organisms under certain circum- 
stances are found within the body of phagocytes, and for this reason it 
has been believed that the phagocytes devour bacteria. This theory has 
also been advanced by Metchnikoff and others in explanation of immunity 
to disease. Immunity or susceptibility, it is claimed, depends upon the 
ability or inability, respectively, of the phagocytes to destroy micro-organ- 
isms. This theory may be entirely correct, but as yet it is not universally 
adopted. One of the strongest arguments against it is the fact that infec- 
tious diseases can be produced by the peculiar poisons or waste products 
elaborated by the bacteria and without the presence of the organisms which 
elaborated the peculiar poison. 

Formation of Pus. — Through the agency of the peptonizing power 
of the micro-organisms lodged at the point of infection the central mass 
of dead tissue, formed by the process of coagulation, and the contiguous 
intercellular substance are liquefied. This process liberates the exuded 
leucocytes which were entangled in the meshes of the intercellular sub- 
stance, and they become mixed with the liquefied material and break down 
into a granular detritus, which, with the dead leucocytes, forms pus. This 
process continues with greater or less rapidity, according to the char- 
acter of the inflammation and the diathesis of the individual, the quantity 
of the pus steadily increasing in amount ; tension of the surrounding 
tissues results, and both the bony and soft structures are destroyed by 
molecular necrosis until the surface is reached, following that course which 
offers the least resistance. This is termed pointing, and through this open- 
ing the fluid contents of the abscess are discharged. During the process 
of the formation of the abscess active cell proliferation in the fixed tissue- 
cells is going on in the outer portion of the wall of leucocytes ; while upon 
the inside of the abscess- cavity a new tissue is formed, known as granu- 
lation-tissue, which by its growth repairs the damage caused by the death 
and liquefaction of the tissues involved in the abscess. This tissue is com- 
posed chiefly of small, round cells with scanty intercellular substance, but 
very rich in capillary blood-vessels, each granulation-point being occu- 
pied by minute capillary loops. 

Location. — According to the common acceptation of the term, an 
alveolar abscess is an accumulation of pus located in the apical space, the 
result of septic inflammation induced by a decomposing gangrenous pulp ; 
and for various reasons it would seem best to restrict the use of the term 
to this particular form of dento-alveolar abscess. It is true, however, that 
abscesses are formed within the dental alveolus which have no connection 
with a gangrenous pulp ; in fact, they are frequently found in the alveoli 
of vital teeth, as, for instance, in pyorrhoea alveolaris and inflammatory 
conditions arising from various forms of irritation and traumatisms of the 
pericementum. 

In the formation of a dento-alveolar abscess the pus is at first confined 
to the apical space, where it is surrounded by bony walls. As the pus 
accumulates pressure is brought to bear upon the surrounding walls ; this 
pressure, together with the dissolving or peptonizing action of the bacteria, 



478 OPERATIVE DENTISTRY. 

causes a rapid cell-necrosis and disintegration of the surrounding cancel- 
lated bone, and a gradually increasing cavity is formed at the apex of the 
root. The tendency of the accumulated pus, assisted by the pressure 
within the cavity, is to seek an exit in a direction that offers the least 
resistance. 

The external or buccal wall of the alveolar process is the thinnest, and 
offers the least resistance to the progress of the accumulated pus ; for this 
reason the abscess usually points upon the buccal aspect of the alveolar 
process, opposite the apex of the root. 

Dento-alveolar abscesses point in three distinct ways after penetrating 
the bony walls : first, directly through the soft tissues ; secondly, by sepa- 
rating the periosteum from the bone and forming a secondary pus- cavity ; 
thirdly, by following the pericementum along the side of the root and 
discharging at the margin of the gum. 

Dento-alveolar abscesses which point directly through the gum-tissues 
are the most common, and rarely present any complications. The second 
form is often complicated with necrosis of portions of bone, and by pene- 
trating the external tissues of the face or burrowing downward into the 
tissues of the neck. For these reasons such an abscess should receive 
prompt attention, in order that the destructive process may be confined to 
the narrowest limits and disfiguration and other more serious consequences 
be prevented. 

The relations of the roots of the incisor and cuspid teeth to the floor 
of the nose are such, in many instances, that alveolar abscesses may point 
through the floor of the nasal fossa and produce a purulent discharge that 
might readily be mistaken for chronic nasal catarrh. The relations of the 
roots of the bicuspid and molar teeth to the floor of the antrum are such 
as to make it even less difficult for an abscess connected with one of these 
teeth to penetrate the floor of the sinus. 

Abscesses in connection with the teeth of the lower jaw may penetrate 
the alveolar process, but fail to penetrate the gum, and by force of gravi- 
tation and the pressure of the accumulating pus make paths for themselves 
between the periosteum and the soft tissues, or between the periosteum 
and the bone, and finally discharge upon the face beneath the chin or the 
jaw. Or they may burrow through the body of the jaw. Abscesses in 
relation with the third lower molars often penetrate the external tissues at 
the angle of the jaw, or they may occasionally burrow downward into the 
neck, forming large pus- cavities in the submaxillary triangle. The writer 
has operated upon several cases of this character, from which pus varying 
in amount from four ounces to a pint had been removed. In some of these 
cases the tissues were so infiltrated with the pyogenic cocci that for weeks 
after the original abscess had healed, and the offending tooth had been re- 
moved, crop after crop of phlegmonous abscesses appeared in the neigh- 
borhood, located in the cellular tissue immediately beneath the skin. 

Another form of dento-alveolar abscess is one which has no external sinus 
for the discharge of the pus. These cases have been for this reason designated 
as blind abscesses. The term is, however, hardly a correct one, for the 
pus discharges through the pulp-canal, which becomes its sinus, and it is 



DENTO-ALVEOLAR ABSCESS. 479 

therefore not a blind abscess. These abscesses are usually small, and, as a 
rule, have not been very painful ; in fact, all of the acute symptoms have 
been greatly modified by reason of the ready exit of the pus from the 
beginning of the suppurative process. 

Abscesses which discharge along the side of the root and find exit at 
the margin of the gum are sometimes confounded with the so-called blind 
abscess, but in these cases a careful examination will reveal the fact that 
there is no discharge through the pulp-canal. Many times this form of 
abscess is associated with pulpless teeth whose roots have been filled, but 
in which there is sufficient septic irritation to keep up a chronic discharge 
of pus through the sinus which has been formed by the side of the root. 

CHRONIC DENTO-ALVEOLAR ABSCESS. 

A chronic dento-alveolar abscess is one which has passed through the 
acute stage, but in which the after-symptoms have been greatly modified. 
Acute dento-alveolar abscesses rarely heal spontaneously ; there is, how- 
ever, a partial filling up of the pus-cavity by the growth of the granu- 
lation-tissue which lines it. But there is usually a sufficient amount of 
decomposition of tissue and the growth of micro-organisms within the 
abscess cavity and the pulp -canal to keep up a continuance of the sup- 
purative process and a discharge of pus. 

Occasionally a dento-alveolar abscess may present chronic symptoms 
from the very beginning of the suppurative process, as, for instance, in 
blind abscess. In many of these cases no marked inflammatory symptoms 
have developed at any time, and yet there is often a prolonged and obsti- 
nate irritation at the apical space and a persistent accumulation of pus, 
which finds an exit through the pulp-canal. 

Abscesses which have pointed through the external tissues of the face 
are nearly always of a chronic type, particularly those which have had 
their origin in ancient traumatisms, perforation of the cementum, broken 
instruments within the root-canal, or from an impacted position of a tooth. 

Symptoms and Diagnosis. — The symptoms of acute dento-alveolar 
abscess in its early stage are the same as in acute septic apical pericemen- 
titis. If inflammation of the pericementum of a pulpless tooth with the 
pulp-chamber open has continued for from twenty-four to thirty-six hours, 
pus has doubtless been formed. With the formation of pus the symptoms 
become more aggravated. The gums in the region of the affected tooth 
assume an inflamed condition ; the pain is of a deep throbbing character, 
which at times is almost intolerable. With the formation of pus there is 
often a rigor, or chilly sensations are experienced, lasting for an hour or 
two. This is followed by an elevation of temperature ; the more severe 
the rigor the higher the fever will run. The temperature may vary from 
101° to 103° or 105° F., according to the virulence of the infection and the 
susceptibility of the individual to septic irritation. 

As soon as the pus penetrates the bony walls of the abscess and escapes 
into the soft tissues the severity of the pain is abated, but the tissues 
begin immediately to swell, and the swelling may be so great when the 
affected tooth is located in the upper jaw, as to close the eye, or when 



480 OPERATIVE DENTISTRY. 

located in the lower jaw to cause great swelling of the neck, especially in the 
submaxillary triangle. The cervical lymphatic glands may also become 
swollen and tender, and sometimes suppuration takes place in them. The 
pus occasionally collects in great quantity, and under such circumstances it 
is not uncommon for such abscesses, when located in the upper jaw in con- 
nection with the incisors and cuspids, to rupture into the nasal cavity, and 
for the bicuspids and molars to discharge into the antrum of Highmore, 
or through the external tissues of the face, while those in the lower jaw 
may rupture through the external tissues of the jaw or burrow down- 
ward, following the fascia of the neck, and rupture at any point above the 
clavicle. Cases are on record where abscesses in connection with the lower 
third molars have burrowed downward and discharged into the larynx and 
at points upon the chest as low down as the mammary glands. Infection 
and swelling of the lymphatic glands of the neck is a frequent accompani- 
ment of alveolar abscesses, while metastatic abscesses have been formed in 
various parts of the body as a result of the invasion of the blood-current 
by the organisms of the abscess. 

Dento-alveolar abscesses which discharge into the nasal fossa have been 
mistaken for cases of chronic nasal catarrh, while such abscesses discharging 
into the maxillary sinus are productive of the most troublesome cases of 
empyema of this sinus. 

The diagnostic signs of acute dento-alveolar abscess are discoloration of 
the tooth, no response to the thermal test, showing that the pulp is dead, 
tenderness to percussion, elongation of the tooth, looseness in its alve- 
olus, tenderness to palpation over the apex of the root, swelling and 
inflammation of the gum, and fluctuation at that location where the 
abscess is about to point. The character of the pain is more intense 
during the formation of the pus than at any other time, and is relieved 
as soon as the swelling of the external tissues begins. 

In the differential diagnosis it must be remembered that a sequestrum 
of necrosed bone or an impacted tooth would produce symptoms so nearly 
like those of dento-alveolar abscess as to be readily mistaken for that condi- 
tion. In fact, sometimes the only way that a differential diagnosis can be 
made out is by tracing the sinus to the sequestrum or to the impacted tooth. 

Prognosis. — The prognosis of simple uncomplicated dento-alveolar 
abscess is generally good if proper antiseptic methods of treatment are 
instituted. Occasionally, however, no method or amount of treatment 
will avail to save some of these teeth. In certain individuals the death 
of the pulp means the speedy loss of the tooth from chronic septic peri- 
cementitis and resorption of its alveolus. Fortunately these cases are not 
very common, but when they do present themselves they cause an untold 
amount of anxiety during the effort to preserve them, and deep chagrin 
when these efforts prove futile and the tooth has to be extracted. 

"When the alveolar abscess is complicated with necrosis of the alveolar 
process surrounding the tooth it is commonly lost with the necrosed bone ; 
but when the external plate alone or the mesial or distal septum only are 
lost, the tooth may in many instances be retained and restored to health 
and usefulness. 



DENTO-ALVEOLAR ABSCESS. 481 

When it is complicated with perforation of the floor of the nasal cavity 
or of the maxillary sinus a somewhat serious problem is presented. It 
would at first thought seem that the only treatment that would be required 
to cure such cases was to properly sterilize the pulp-canals and to fill 
them. Such treatment does not, however, always succeed, for the reason 
that there is very great difficulty experienced in properly sterilizing 
them, on account of the constant draining of the fluids of the nasal 
cavity and of the antrum into the canals ; in fact, in some of these cases it 
is impossible to ever get them in such a condition of dryness as to warrant 
the introduction of a root-filling. Again, it is not at all uncommon to find 
the apices of the roots of these teeth more or less eroded ; and when the 
abscess has become chronic, if they are not eroded they are covered with 
concretions of calcific matter, which makes it impossible for the roots 
of these teeth to ever again assume a healthy condition. The prognosis 
is, therefore, unfavorable, and the sooner such teeth are removed the 
better. Their extraction often becomes imperative as a means of correct- 
ing the discharges from the nose and from the maxillary sinuses. 

When the alveolar abscess is complicated with a sinus which discharges 
upon the face it becomes a matter of considerable interest to the patient 
as to whether the offending tooth can be saved and the disfiguration of the 
face corrected if the tooth be permitted to remain. Such cases do not ordi- 
narily present any serious difficulties in their treatment. One such case 
associated with a cuspid tooth, which was referred to the writer by a 
medical friend, discharged by the side of the nose just below the inner 
canthus of the right eye, and resisted all efforts to puncture the apical 
foramen or to force antiseptic remedies through it ; and as no improve- 
ment could be seen in the case after repeated treatments extending over a 
period of more than two weeks, it was thought advisable to remove the 
offending tooth, when, upon extracting it, a steel broach was found in the 
upper fourth of the canal, and projecting beyond the foramen a full half- 
inch. Comment is unnecessary. The discharges immediately ceased, and 
the sinus closed in less than a week. Later the discolored tissue was 
removed by an elliptical incision, the skin loosened from the fascia and 
brought together with very fine silk sutures ; the wound healed by first 
intention, and the only scar left was a delicate straight line following the 
natural line of the face. 

Dento-alveolar abscess is sometimes complicated with perforation of the 
cementum. Perforations of the pulp-canal which involve the pericemen- 
tum may be caused in several ways : First, by caries which has operated 
from within the pulp-canal ; secondly, the absorptive action of the osteo- 
clasts which, as a result of inflammation, have attacked the cement-tissue 
at various locations upon the side of the root and penetrated to the pulp- 
canal ; and thirdly, by the injudicious use of the reamer or drill in en- 
larging the pulp-canal preparatory to filling, or forming it to receive a 
post for an artificial crown. Such cases often present a condition of 
chronic abscess which may discharge through the pulp-canal, by the side 
of the root at the margin of the gum, or through a sinus in the external 
tissues. 

31 



482 OPERATIVE DENTISTRY. 

The effect of such a perforation is to establish inflammation of the peri- 
cementum and sometimes ulceration. Perforations which are the result 
of caries or absorption are irregular in outline, and the edges are sharp 
and rough. These conditions present an added source of irritation which 
aggravates the inflammation already existent and stimulates the growth of 
granulation-tissue. This new tissue enters the perforation and extends 
into the pulp-canal, sometimes completely filling it, and by its appearance 
and hypersensitive condition has misled some of the most careful observers 
into the belief that they were dealing with an hypertrophied pulp. Under 
such circumstances the application of arsenic for the devitalization of what 
appeared to be pulp-tissue might prove exceedingly disastrous. The ut- 
most care should be exercised in reaching a diagnosis in these cases. 

Perforations which are the result of a surgical traumatism have well- 
defined edges, as a rule, and if immediately treated upon scientific prin- 
ciples will, in a considerable number of cases, respond kindly to such treat- 
ment and the tooth be finally conserved. But when the case is permitted 
to run along without proper treatment inflammation of the pericementum 
follows, and the conditions which have just been described may develop, 
or chronic suppuration may be established. 

In those cases located in the lower jaw where the abscesses burrow 
through the body of the jaw and open upon the face or beneath the chin, 
or extend into the soft tissues of the submaxillary triangle, or into the 
deeper tissues of the neck, immediate extraction should be recommended 
in the former and imperatively demanded in the latter. In the former 
the prognosis is considered unfavorable, for the reason that in a majority of 
these cases the apices of the roots will be found more or less eroded as a 
result of the continued inflammatory conditions. While in the latter the 
prognosis is considered grave by reason of the tendency to diffuse cel- 
lulitis and the great danger that acute septicaemia may be developed by 
the absorption of the ptomaines, or that pyaemia may be established by the 
invasion of the pyogenic organisms or the entrance of pus into the blood- 
current, and the formation of metastatic abscesses in remote portions of 
the body. 

Treatment.— The treatment of acute dento-alveolar abscess often de- 
mands vigorous constitutional treatment to abort the inflammatory process, 
to allay the suffering incident to the process of pus formation and the pene- 
tration of the bone for the escape of the pus, and to control the high tem- 
perature induced by the severe irritation and the absorption of certain 
waste products of the micro-organisms. 

The constitutional measures which are usually employed in the treat- 
ment of alveolar abscess have already been indicated in the preceding 
chapter on Pericementitis. 

Local Treatment. — The treatment of acute alveolar abscess in its 
early stages, before a fistula has been established, comprehends, — 

1. Efforts to abort the inflammation by the employment of local thera- 
peutic measures, surgical and medicinal. 

2. Limiting, as far as possible, the destruction of tissue by controlling 
the suppurative process. 



DENTO-ALVEOLAR ABSCESS. 483 

3. The earliest possible evacuation of the pus. 

4. The promotion of the healing process. 

Inasmuch as the primary seat of the infection which establishes the 
suppurative process in the apical space is the pulp-canal, efforts should 
be first directed to gaining an entrance to this seat of infection and thor- 
oughly removing all infectious material. It is an axiom in general medi- 
cine and surgery that to cure a disease the cause must first be removed. 
Having removed, as far as may be, by mechanical means, the gangrenous 
and putrefying pulp, the second step is to render the canals aseptic by 
saturating or irrigating them with antiseptic drugs, and thirdly, by local 
depletion, induced by scarification of the gums in the neighborhood of 
the affected tooth, to promote bleeding by warm water held in the mouth 
or by counter-irritation of the gum over the diseased tooth, as indicated 
in the chapter on Pericementitis. 

If these measures fail to abort the suppurative process by reason of the 
escape of the infectious material and pyogenic bacteria into the apical 
space, it becomes necessary, in order to limit the destruction of tissue, to reach 
this focus of infection by surgical means. This may be accomplished in 
some cases through the apical foramen and the pus evacuated through this 
channel ; but if this is not possible, it may be reached by trephining the 
alveolar plate, or by the extraction of the tooth. In all cases where the 
tooth is valuable and the general conditions of the health of the individual 
do not contraindicate, every effort should be made to save the tooth. But 
in certain conditions of the system, as in tuberculosis, syphilis, continued 
fevers, anseinia, general debility, nervous prostration, and pregnancy, the 
conservation of the tooth is contraindicated, as in all but the latter the 
vital resistance of the tissues is so reduced that great destruction of tissue 
is likely to attend all suppurative processes ; while in the latter, if the 
period of confinement is near, it is imperative that all suppurative condi- 
tions be abated before parturition sets in, on account of the great danger 
of septic infection at this period, and the establishment of puerperal 
fever or acute septicaemia from the presence of suppurative foci in other 
portions of the body, and the infection being carried in the blood- 
current. 

Blind abscesses should be permitted to drain through the pulp-canal for 
forty-eight hours or longer, in fact, until pericemental irritation ceases, 
before dressings are applied to the root-canal. 

In trephining the alveolar plate two methods have been suggested. 
Dr. Black's method is to perforate the gum-tissue by the escharotic effect 
of carbolic acid, full strength, carried upon a serrated plugger of suitable 
size, and applied to the gum at the point selected for the ^perforation, and 
the instrument gently rotated. As the carbolic acid penetrates the tissue 
it renders it anaesthetic, while the rotation of the serrated instrument cuts 
away the tissue which has been destroyed by the escharotic action of the 
drug. In this way the gum is penetrated without causing pain. A sharp, 
spear-pointed drill is now substituted for the plugger, and the bony plate 
perforated in the same comparatively painless manner. The only objection 
to this method is the necessarily slow procedure, as the instrument cannot 



484 



OPERATIVE DENTISTRY. 



be advanced raore rapidly than the penetration of the carbolic acid renders 
the tissues anaesthetic. 

A second method is to inject subgingivally a two per cent, solution of 
cocaine hydrochlorate over the root of the affected tooth ; make a triangu- 
lar flap in the gum, the point towards the crowns of the teeth ; then, with 
a spear-pointed drill (Fig. 575) or a small trephine (Fig. 576), penetrate 



Fig. 57' 



Fig. 575. 

ft ^ 



Fig. 57( 



I 



I 

Spear-pointed drills. Trephines. 




the alveolar plate at the apical space with the engine- drill (A) or hand- 
drill (B), as shown in Fig. 577, as suggested by Garretson. By this method 
the operation may be done entirely without pain, except from the injection 
of the cocaine solution, which is only momentary. On reaching the apical 
space, the focus of infection may be broken up and the abscess- cavity irri- 
gated with suitable warm antiseptic solutions, and the opening in the gum 
and the alveolar plate kept patulous by the introduction of a few strands 
of antiseptic silk or cotton. The wound and the abscess- cavity should be 
irrigated two or three times per day until the inflammatory symptoms are 
abated, when the case may be treated after the usual manner, and as soon 
as the conditions are favorable the pulp-canals should be filled. 

u Ubi pus ibi evacuo" when there is pus evacuate it, is as wise a 
surgical rule for to-day in the treatment of acute abscesses as when it was 
first enunciated centuries ago. The expectant treatment, which has until 
recent years been the general practice, is quite rapidly giving way to the 
more rational method of cutting down upon the seat of suppuration and 
giving immediate exit to the accumulated pus, as by this method the dis- 
ease is cut short and much suffering saved the patient. 

A safe rule to follow in all cases of acute alveolar abscesses which have 
not yet pointed is to apply the knife and give immediate exit to the accu- 
mulated pus, for by so doing great relief is afforded the patient, while 
the destruction of tissue is thereby limited, and the dangers from general 
septic infection are greatly reduced. 

The promotion of healing is accomplished by thorough antisepsis of the 



DENTO-ALVEOLAR ABSCESS. 485 

pulp-canals and the abscess-cavity, and securing rest for the tooth during 
its restoration to health. 

In the treatment of abscessed teeth which have discharged into the 
nasal fossa or the antrum of Highinore, extraction is the only satisfactory 
method of treatment, while in those which have penetrated the external 
tissues of the face it is also generally the safest practice, especially in those 
cases which do not respond to the ordinary methods of treatment, such as 
sterilization of the pulp-canals, abscess-cavity, and fistulous tract, and the 
employment of such escharotics as creosote and carbolic acid pumped 
through them, or drawn through them by the cupping device recommended 
by Drs. T. M. Hunter* and Burchard.f This device is formed of the 
ordinary rubber polishing-cup mounted upon a mandrel, and used by first 
moistening the inside of the cup and pressing it over the fistulous opening 
until the air is excluded, when the vacuum which has been created by 
allowing the cup to assume its natural shape will empty the pus- cavity, 
and if creosote, carbolic acid, or other fluid substance has been placed in 
the pulp-canaL it will be drawn through the fistulous tract and appear at 
its exit. 

In the treatment of abscesses arising from devitalized or impacted teeth 
located in the lower jaw which have not pointed, but in which the pus 
has accumulated in considerable quantities and burrowed downward into 
the submaxillary and carotid triangles, the immediate extraction of such 
teeth and the evacuation of the pus by external incision is imperatively 
demanded. In opening such abscesses the incision should be made at the 
lowest point of the pus-cavity, and, on account of the danger from wounding 
the important blood-vessels located in these parts, the incision with the 
bistoury should only be carried through the skin, when, with a pair of 
haemostatic snap- forceps with the blades closed, the point may be insinuated 
between the fibres of the muscles and carried into the abscess, and as they 
are withdrawn the blades may be opened and the fibres of the muscles 
still farther separated. By this method of tunnelling the tissues all danger 
of wounding the blood-vessels is entirely obviated. 

After the evacuation of the pus the cavity is thoroughly irrigated, a 
drainage-tube inserted, and the external wound dressed with several layers 
of absorbent cotton liberally sprinkled with powdered boric acid or iodo- 
form, and a bandage applied. 

Of course it is understood that so formidable an operation will require 
a general anaesthetic and the confinement of the patient to the bed for 
several days. 

Chronic Alveolar Abscess. — The treatment of the ordinary chronic 
alveolar abscesses with fistulous openings should follow the same line of 
procedure as that just laid down for the treatment of acute abscess with 
fistulous opening. 

Abscesses which are associated with perforations of the walls of the 
root communicating with the pulp-canal are in a very large majority of 

* Dental Cosmos, vol. xxxiv. p. 82. 
t Burchard's Dental Pathology, p. 379. 



486 OPERATIVE DENTISTRY. 

instances in a chronic state when presented for treatment. In those cases 
which are the result of a surgical traumatism of recent date, occurring at 
any point above the middle of the root (the morsal half), the chances for 
successful treatment are very good indeed, provided resorption of the root 
in the immediate neighborhood has not begun. 

The perforation may be closed in the following manner : after having 
arrested the hemorrhage with tannin and glycerol or phenol sodique, and 
the cavity thoroughly sterilized and maintained in that condition during 
the balance of the operation, a disk of ~No. 60 gold-foil, or, better, a disk 
of tin cut from a sheet of No. 4 tin-foil which had been doubled upon 
itself four times, or sixteen thicknesses, may be dipped in chlora-percha 
and laid over the opening and carefully pressed into place, the canal filled 
with gutta-percha, and the cavity in the crown sealed with zinc oxyphos- 
phate. 

In those cases which are the result of pathologic states the treatment 
becomes much more difficult. When the pulp-canal is filled with granula- 
tion-tissue, this can be removed by first applying a local anaesthetic like 
cocaine or eucaine, which in many instances can be employed cataphori- 
cally. Or an ethereal solution of chloretone — equal weights of each — may 
be applied upon a pledget of cotton. As soon as it is thoroughly anaes- 
thetized it can be removed with a small sharp-pointed lancet, delicate 
enough to enter the pulp-canal for at least half its depth. After the bleed- 
ing has been arrested, the cavity may be packed with cotton dipped in 
powdered boracic acid and sealed with gum sandarach. These dressings 
should be renewed every day for a week, when the canal may be sterilized 
and the lower half filled with a gutta-percha point, the perforation covered 
as just described, and the balance of the cavity filled with gutta-percha. 
If the first treatment is not successful, try again and again, if the impor- 
tance of the tooth will warrant it. If, however, after repeated trials the 
tooth remains tender and irritable, it will be the wiser plan to extract it. 
The same is true of those perforations which occur at that portion which 
may be termed the apical half of the root. In these cases gutta-percha is 
the only reliable material which can be used for closing perforations in 
this part of the canal. The uncertainty attending the adjustment of the 
metal disk to the perforation in such a location, or even adapting a gutta- 
percha pellet over it that will not produce pressure, is so great that they 
rarely prove successful. A perforation such as would be made by a drill 
passing through a curved root is usually so clean cut that it can be readily 
closed by a pellet of tin-foil or gutta-percha, but the septic material still 
remains in the curved extremity of the root, where it will become a men- 
acing source of infection and irritation. It is better, therefore, under such 
circumstances, to extract the tooth at once rather than to attempt its 
conservation. 

In those cases, however, which present an obstinate suppurating condi- 
tion, which persists after the most thorough antiseptic treatment of the pulp- 
canals, the abscess- cavity, and the fistulous tract, radical treatment becomes 
necessary. This may comprehend, first, the curettement of the fistulous tract 
and the abscess-cavity ; second, the amputation of the apical end of the 



DENTO-ALVEOLAR ABSCESS. 487 

root in situ ; third, the extraction of the tooth, amputation of the apical 
end of the root, sealing of the canal, and replantation of the tooth. 

Curettement of the abscess -cavity and the fistulous tract is often employed 
to stimulate the healing process in indolent ulcerations and abscesses. The 
object of this procedure is to change the indolent character of the granu- 
lating process into one of an active character, and thus promote the heal- 
ing process. 

The procedure is as follows : first inject a few minims of a two or four 
per cent, solution of cocaine hydrochlorate, eucaine, or chloretone into the 
pus-cavity through the fistulous tract. As soon as the parts have become 
anaesthetic, which will be in from three to five minutes, slit open the fistula 
to its base or connection with the abscess- cavity ; enlarge the opening in 
the alveolar plate sufficiently to admit a good-sized straight spoon exca- 
vator. Carefully examine the apex of the root for any rough or denuded 
points, and if none exist the case may be considered as offering a fair 
chance of being cured. The next step is to thoroughly curette the whole 
surface of the abscess- cavity with the spoon excavator, after which the 
debris and blood may be washed away and the cavity packed with a strip 
of boric acid gauze or carbolized gauze. The root-canal should have been 
previously sterilized and packed with an antiseptic dressing, or the canal 
may be permanently filled with gutta-percha. In the opinion of the 
writer the better plan is to permanently fill the root-canal first, and then 
at the same sitting, or one arranged a few days later, proceed with the 
operation of curettement. The after-treatment of the abscess-cavity con- 
sists of removing the dressing once each day, thorough irrigation with a 
saturated boric acid solution, two per cent, carbolic acid solution, or with 
cinnamon- water, and redressing with a strip of gauze. The gauze should 
be packed lightly so as not to injure the delicate granulation-tissue which 
usually begins to form immediately after the operation. As the cavity 
grows smaller less and less gauze will be required, and finally it may be 
left out altogether and the external opening allowed to close. Irrigation, 
however, must be kept up until the wound is entirely healed. Frequent 
use of the irrigating fluid should be recommended as a mouth-wash, and 
the patient instructed to use it every two hours during the day and once 
or twice during the night as a means of controlling the septic condition 
of the mouth. 

If, however, upon examining the apex of the root it is found to be de- 
nuded and roughened, or covered with calcific deposits, it will be necessary 
to amputate the diseased portion of the apex. 

Amputation of the Apex in Situ. — Before undertaking this opera- 
tion the pulp-canal should be thoroughly sterilized and filled with gutta- 
percha, and the crown-cavity protected with a filling of zinc oxyphosphate. 
The fistula is then slit open with a small bistoury down to the apex 
of the root, the edges of the incision held away, and a section of the 
alveolar plate removed with the trephine in the dental engine sufficiently 
large to thoroughly expose the apex of the root, or a large fissure-bur may 
be used for the same purpose, and the opening in the alveolar plate en- 
larged by sweeping it around the edges. Hemorrhage may be controlled 



488 OPEEATIVE DENTISTRY. 

by packing the wound with cotton saturated with phenol sodique or tannin 
in glycerol. The apex of the root, after the hemorrhage has ceased, can 
be readily seen through the opening. The eroded portion should now be 
amputated with a small, sharp fissure-bur, revolved at high speed with the 
dental engine. The edges of the stump can be smoothed with a fine finish- 
ing-bur, or with a sharp excavator or scaler. The cavity should next be 
thoroughly irrigated, all debris and blood-clots removed, and the cavity 
packed with a strip of gauze and powdered boric acid. The edges of the 
incision may be brought together at the upper portion and maintained in 
. position by one or two sterilized horse-hair sutures, the end of the gauze 
being left at the most dependent portion of the incision, where it may be 
grasped and removed after twenty-four to forty-eight hours, according as 
the circumstances of the case may indicate. Meanwhile the mouth must 
be frequently irrigated with a suitable antiseptic lotion. At the end of a 
couple of days the dressing is removed, the cavity thoroughly irrigated 
with antiseptic solutions, and the patient instructed to keep the mouth 
clean by the frequent use of the antiseptic mouth- wash which has been 
selected. Teeth which have been treated after this method should not be 
filled with gold for several months after the operation. 

A fair per cent, of the cases of amputation in situ prove successful, but 
the writer is of the opinion that the more heroic operation of extraction 
and replantation (see following chapter) gives a larger percentage of 
cures in obstinate cases of alveolar abscess than the preceding method 
of operation. 

Alveolar Abscess associated with Deciduous Teeth. — Little chil- 
dren are often great sufferers from alveolar abscesses associated with their 
temporary teeth. If the child is timid and greatly afraid of being hurt, 
the difficulties presented by this condition render the duty of the operator 
to relieve the little sufferer as quickly as possible a somewhat arduous 
task. 

Patience, gentleness, and kindness, however, backed by a little firm- 
ness, will usually overcome the timidity of the child, and in large measure 
banish the fear of being hurt, so that it becomes possible to do all that is 
necessary to give the desired relief. 

The suppurative process occurring in children is never so severe as in 
adults, as the tissues of children are soft and break down very readily 
when subjected to inflammatory processes. For this reason the time con- 
sumed by the pus in finding its way through the gum is much less than in 
the adult. And although the pulse and the temperature may run high 
during the inflammatory process, and the swelling and congestion of the 
tissues be very considerable, the suffering is not so great as in adults. 

The treatment of these cases does not differ from that already indi- 
cated. Immediate relief may usually be obtained by opening the abscess 
by an incision in the gum. This may be done with so little pain to the 
child, if the bistoury with which the incision is to be made has a keen 
edge, and the attention of the child is diverted to some pleasing subject 
when the incision is made, as to hardly attract its notice. When all is 
over the child usually expresses surprise that it hurt so little. With chil- 



DENTO-ALVEOLAR ABSCESS. 489 

dren who are unmanageable it becomes necessary to use a general anaes- 
thetic, and under certain circumstances it is best to extract the tooth rather 
than to attempt its conservation. 

A very large percentage of pulpless temporary teeth can be rendered 
healthy and useful so long as nature requires their service for the purpose 
of mastication by thorough sterilization of the pulp-canals and filling them 
with gutta-percha. Dr. W. H. White a few years ago introduced a new 
material for filling root-canals in children's teeth particularly, — viz., 
balsam del deserto, which it is claimed does not in the least interfere with 
the resorptive process of the roots of these teeth in their exuviation. It 
is especially useful in filling abnormally large canals. 

Occasionally a case will be presented in which root-fillings are not 
tolerated by the tissues. Such teeth should be extracted at once, as re- 
peated inflammation and the formation of abscesses are liable to cause 
injury to the advancing tooth. 

Chronic alveolar abscesses are prone to cause swelling of, and some- 
times metastatic abscesses in, the cervical lymphatic glands of children of 
the strumous or tuberculous diathesis. Under such circumstances the 
immediate extraction of these teeth is imperatively demanded. 

Constitutional treatment is also demanded in these cases for the build- 
ing up of the bodily vigor. Much can be done for these children by giving 
them an abundance of out-door life and plenty of wholesome, nutritious 
food. Sometimes drugs are indicated, in the form of cod-liver oil, iron, 
arsenic, beef-peptones, the bitter tonics, etc., but best of all is sunlight, 
pure air, plenty of exercise, and the institution of a scrupulous hygienic 
condition of the mouth. 



CHAPTER XXX. 

REPLANTATION OF THE TEETH. 

Definition. — Replantation, from the Latin replantare, to plant again. 
Reimplantation, from the Latin reimplanto, to implant again. 

The operation of replantation or reimplantation of teeth is the replacing 
of a tooth in the alveolus from whence it had been removed by accident or 
by design. 

Replantation is practised at the present time for three conditions : 

First — When a tooth has been dislodged by an accidental traumatism, 
such as might result from a fall or a blow. 

Second. — When a tooth has been removed as a result of an accidental 
surgical traumatism, such as the dislodgement of a tooth by the mouth- 
prop or mouth-gag during the administration of a general anaesthetic pre- 
paratory to the extraction of a tooth, or the slipping of the forceps in the 
extraction of a tooth, which causes the dislodgement of its neighbor or one 
in the opposite jaw. 

Third. — When a tooth is the subject of a persistent alveolar abscess 
which does not respond to the ordinary methods of treatment. 

The degree of success which attends the replantation of teeth depends 
upon the presence and healthful condition of the pericementum, the 
length of time that the tooth has been removed from its alveolus, the 
physical condition of the patient at the time of the operation, the immo- 
bility of the tooth during the process of forming its new attachments, and 
the hygienic condition of the mouth. 

The discussion of the first and second conditions will be reserved for the 
chapter on "Dislocation of the Teeth." 

The treatment of persistent alveolar abscess by extraction and re- 
plantation is generally practised as a dernier ressort when all other methods 
have failed. 

Obstinate alveolar abscesses are usually caused by a crooked root, an 
abnormally small root-canal which makes it impossible to remove or render 
innocuous the retained septic pulp -material, or it is caused by perfora- 
tions of the root made in attempts to open small root- canals, calcareous 
deposits upon the apex of the apical end of the root, or erosion of the 
apical end of the root, which is accompanied by a more or less persistent 
discharge of pus, either through the external or internal plate of the 
alveolar process or through the alveolus at the neck of the tooth. 

Occasionally cases will be found in which no discharges are present, 
but instead a chronic induration of the surrounding tissues ; or, as in the 
superior teeth, the discharges may find their way into the antrum of High- 
more or the anterior nasal passages, and possibly mislead the operator into 
490 



REPLANTATION OF THE TEETH. 491 

the belief that lie has a ease of empyema of the antrum or of ozsena to 
deal with.* 

These teeth are usually sooner or later condemned as worthless mem- 
bers of the economy, and are removed. 

Many of these teeth with suitable treatment may be rendered healthy 
and useful for an indefinite period. 

Eeplantation is only admissible in the anterior teeth, including the 
bicuspids. The molars are capable of being replanted only in exceptional 
cases when there is fusion of the roots and they assume a conical form, 
and occasionally a lower molar when the roots are perpendicular to the 
crown. 

It will be generally conceded that attempts to cure such cases as those 
just mentioned by the ordinary methods usually prove unsuccessful, and 
that eventually the teeth are lost. This results from the fact that such 
operations are largely, per force, only guesswork. If the root is curved at 
a more or less acute angle it is difficult to follow the canal with the broach 
or Donaldson bristle, and many times quite impossible, or if the canal is 
abnormally small, the finest Donaldson bristle may not enter it at all. 
Beaming the canal is unsafe, and under these conditions the various anti- 
septic fluids and liquid filling-materials are unsatisfactory because they do 
not always penetrate to the end of the canal, and consequently septic 
material remains in the pulp-canal and keeps up a constant irritation. 

In cases of erosion of the apical end of the root, amputation of this 
portion in situ is frequently unsuccessful in curing the disease owing to the 
difficulties in smoothing the stump and perfectly filling the apical foramen. 

The same may be said of attempts to plug perforations in the sides of 
the root. 

Eoughened surfaces and foreign substances are not kindly borne by the 
tissues which surround the roots of the teeth ; it is therefore imperative 
that all such hinderances to a return to the normal condition be reduced to 
a minimum. For these reasons it would seem preferable to extract and 
replant such teeth if they do not speedily prove amenable to treatment by 
the usual methods ; for, with the tooth in the hand, the root can be 
minutely inspected, and any eroded portion amputated and the surfaces 
finely polished. The pulp-canal can be reamed out and cleansed without 
the fear of perforating its sides, the canal filled and the apical foramen or 
a perforation plugged with gold and carefully finished, and the whole thor- 
oughly sterilized. None of these operations are possible with the same 
degree of perfection while the tooth is in situ; they must, perforce, be more 
or less imperfect, and just in that degree will they produce irritation and 
the more serious inflammatory processes. 

The question might very properly be asked, Are the operations of re- 
plantation and transplantation of freshly extracted teeth having the peri- 
cementum attached founded upon physiologic law and sound surgical 
principles ? The answer is, Yes ; quite as much so as are the operations 
of skin and bone grafting, and no one condemns these. Union with the 

* Dental Cosmos, vol. xxxiv. p. 464. 



492 OPERATIVE DENTISTRY. 

tissues with which they are placed in contact is the result of the same vital 
processes ; the surgical conditions are nearly identical in each of them, and 
success is as certain in the one as in the other, provided the same aseptic 
conditions can be maintained until union is complete. 

The failure of replanted teeth to unite with their alveoli is much less 
common than with transplanted teeth ; at least, the personal observation 
of the writer bears out this statement. The immediate cause of failure is 
usually suppurative inflammation, induced either by mobility of the tooth, 
which constantly breaks up the attachment of the plastic exudate, or septic 
conditions of the tooth or of its alveolus at the time of the operation, or 
inoculation afterwards from a septic condition of the mouth. 

The failures which occur later— viz., after attachment has taken place — 
are more difficult to understand. 

In these cases the surfaces of the roots are attacked by the osteoclasts, 
and gradually honey-combed or masses of pericemental tissue and dentin 
are dissolved at various locations about the apex, leaving large cavernous 
excavations with sharp edges. Suppuration accompanies or follows the 
work of the osteoclasts ; the tooth becomes loose, and is sooner or later 
exxDelled from the jaw as a foreign substance. 

In explanation the writer would venture the opinion that these phenom- 
ena are due to irritation induced by septic conditions resulting from decom- 
position of the organic material contained in the dentine, and that in the 
form of a gas or effluvium it penetrates the cementum, and coming in 
contact with the pericementum and surrounding tissues, sets up this retro- 
grade metamorphosis. 

There are certain individuals for whom it would not be wise to under- 
take this operation, — viz., those suffering from general anaemia, tubercu- 
losis, and syphilis. Such individuals are never good subjects for surgical 
operations, as their tissues are very irritable, do not, as a rule, heal 
readily, and are prone to suppuration ; consequently replantation, trans- 
plantation, and implantation, if performed upon such persons, are likely to 
prove unsuccessful. 

Many of the failures from these operations have been associated with 
one or the other of these diseases. Great care should therefore be exer- 
cised in the selection of the cases upon which to operate. Carelessness in 
this regard can only result in failure. Of the more than forty operations 
of this character which it has been the privilege of the writer to perforin, 
it has been thus far his misfortune to record only a single failure, although 
they have comprised all grades and durations of the disease, several of 
very long standing, ranging from five to fifteen years. 

The character of the union which takes place between the root of the 
replanted tooth and its alveolus has not so far been positively demon- 
strated. The writer therefore feels that he may offer a few thoughts which 
may tend towards an elucidation of this question. 

Applying the methods used in physical diagnosis to these cases, we find 
that percussion gives the most marked signs. 

Taking the percussion note of normal teeth, produced by striking the 
tooth with a steel instrument, as the standard of pitch, we find that as 



REPLANTATION OF THE TEETH. 493 

inflammatory conditions of the alveolus advance the percussion note be- 
comes lower and duller, while, on the other hand, as these symptoms sub- 
side the note assumes a clearer and higher pitch. This lowering of the 
tone is doubtless the result of a thickening of the pericemental membrane 
and its increased vascularity. The percussion note given by a large per- 
centage of replanted teeth a few months after the operation, or when union 
is complete, is much clearer and higher pitched than that of the adjoining 
teeth. This is more noticeable in the superior than in the inferior teeth, 
on account of the greater resonance of the superior maxillae. 

These facts would seem to indicate a bony union in these cases between 
the root and its alveolus. 

It would also seem probable that the locations at which this anchylosis 
would most likely occur would be where the pericementum had been 
destroyed or the cement- tissue partially removed ; and there seems no good 
reason why under these conditions reunion may not take place in a some- 
what similar manner to that which occurs in fractured bones. 

In some cases the percussion note is normal, this would indicate a nor- 
mal reunion of the pericementum with the alveolus ; but when the percus- 
sion note is lower and duller, it would be certain evidence of an indurated 
pericementum or other inflammatory symptoms. 

To insure success in these operations the following suggestions should 
be observed : 

1. Exclude anaemic, tubercular, and syphilitic cases. 

2. Secure thorough aseptic conditions of the surfaces of the root and 
pulp-canal by washing and immersing in bichloride of mercury solution, 
1 to 500 of water. 

3. Amputate and smooth all eroded surfaces, but sacrifice as little of 
the pericementum as possible. This is very important, 

4. Hermetically seal the pu^-canal and apical foramen, and any per- 
forations that may exist, with gold fillings. 

5. Curette the abscess-cavity, remove the blood-clot from the alveolus, 
and wash both with the bichloride of mercury solution before replanting 
the tooth. This is the only treatment of the abscess- cavity and of the 
alveolus that will be required. 

6. Secure immobility of the tooth by a ligature or an interdental splint 
until union has taken place. An impression of the teeth of that part of 
the jaw to be operated upon should be taken before the tooth is extracted, 
and a splint of gold made to include one or two teeth upon either side of it. 
After the tooth has been replanted, the splint is applied and secured in 
position with zinc oxyphosphate cement, and allowed to remain for from 
four to six weeks. 



CHAPTEE XXXI. 

TRANSPLANTATION AND IMPLANTATION OF THE TEETH. 

Definition. — Transplantation (Latin, trans, across ; plantare, to plant), 
the operation of grafting tissue from one part of the body to another part 
of the same body, or from the body of one individual to that of another. 

The transplantation of teeth is the operation of transferring a tooth 
from one alveolus in the mouth of an individual to another alveolus in the 
same mouth, or of transferring a tooth from the mouth of one individual 
to that of another. 

The operation of transplanting teeth was, during the days of John 
Hunter, much more extensively practised than it is at the present day. 
The study of the literature of that period and of the intervening years 
shows that as far back as 1783 the operation was falling into disuse, and in 
1810 it was referred to as being consigned to oblivion. The reasons which 
were assigned for giving up the operation were (1) the great danger of 
transmitting specific diseases like syphilis, (2) the frequent occurrence of 
alveolar abscess, (3) the loss of the tooth after a few years from loosening 
or resorption of its root, and (4) objections were raised to the operation on 
moral grounds, as the poor sold their teeth to the rich for a price. 

During the last two decades the operation has been revived, and upon 
the whole has given somewhat better results than those recorded a hundred 
years ago. The teeth which are used are usually sound teeth or healthy 
roots that have been removed in the operation of regulating the teeth or 
to make room for an artificial denture. The introduction of antiseptic 
methods in operative surgery has made it possible to entirely prevent the 
inflammatory symptoms and the formation of alveolar abscesses which 
were before this time so common as a sequel of the operation. The 
danger of transmitting specific diseases has, however, not been overcome, 
although no doubt greater care is exercised in the selection of the teeth 
that are to be used for transplanting by inquiring more carefully into the 
history and physical condition of the individual from whose mouth the 
tooth was taken. One case has, nevertheless, been reported recently in 
which syphilis was said to have been transmitted by the transplantation 
of a tooth taken from the mouth of a syphilitic subject. 

The tendency to ultimate loosening of the tooth and resorption of its 
root after a few years remains the same, and there seems to be no way to 
prevent these untoward results. Teeth which have been treated by the 
most complete aseptic methods are equally liable to be lost by these 
morbid conditions as those which had not been so treated. 

Eeplanted teeth and teeth transplanted from one alveolus to another of 
the same mouth give better results, in the observation and experience of 
the writer, than do teeth transplanted from the mouth of one indivdual to 
that of another. 
494 



TRANSPLANTATION AND IMPLANTATION OF THE TEETH. 495 

The operation is applicable only to the ten anterior or single-rooted 
teeth. It will be seen, therefore, that the operation is confined to rather 
narrow limitations, the confines of which cannot, with any assurance of 
success, be overstepped. 

The same general conditions that promote success or failure in replanted 
teeth are operative in transplanted teeth, — viz., the presence of healthful 
or morbid condition of the pericementum, the length of time that the 
tooth has been removed from its alveolus, the physical condition of the 
patient at the time of the operation, the hygienic or non-hygienic con- 
dition of the mouth, the adaptability or non-adaptability of the tooth to 
its new alveolus, the healthful or morbid condition of the new alveolus, 
and the mobility or immobility of the tooth during the formation of its 
new attachment. 

The most favorable period in which to perform the operation of trans- 
plantation is during youth and early adult life, although it may be suc- 
cessfully performed at any period provided the patient is in vigorous 
health. 

In the selection of a tooth for transplantation, one should be chosen 
which is as near as possible of the same age as the tooth which is to be 
replaced. Teeth which are younger than the one to be replaced are, how- 
ever, more likely to form a healthy union with the new alveolus than those 
which are older. 

The practice of selecting teeth which have been extracted for a con- 
siderable time, where nothing is known of their history or of the physical 
condition of the patient from whom they were taken, should be severely 
criticised for the reasons already mentioned. Too much care cannot be 
exercised in this direction. When a suitable sound, fresh tooth cannot be 
secured, a tooth with a carious crown but healthy root may be selected, 
and an artificial crown of proper color and form grafted upon the root by 
any of the various methods of crowning. 

It is better, also, in selecting the tooth, to choose one with a slightly 
larger, rather than a smaller, root than the tooth to be replaced, as it is an 
easy matter with suitable burs and drills to enlarge, deepen, or change the 
shape of the alveolus to fit the tooth. When the root is too small to fit 
the alveolus immobility cannot be secured, and as a consequence a good 
union does not take place. 

The best results are obtained by completing the operation at the same sit- 
ting. The tooth to be replaced should first be extracted, care being exercised 
not to fracture the alveolus or unnecessarily wound the gum. The tooth to be 
replanted is next extracted, the pulp-canal opened, the pulp extirpated, 
the canal filled with gutta-percha, and the apical foramen and the opening 
in the crown plugged with gold. The whole operation should be performed 
according to the strictest aseptic methods. (See preparation of the tooth 
for replantation, in preceding chapter.) 

The alveolus should then be shaped to receive the new tooth, the 
alveolus and tooth thoroughly washed with a solution of mercuric bi- 
chloride, 1 to 1000 of water. The tooth may now be placed in position 
and retained, if necessary, with a ligature, an impression taken of this 



496 OPERATIVE DENTISTRY. 

section of the mouth, and a metal splint constructed which will cover the 
transplanted tooth and one upon either side of it, and cemented in place 
with zinc oxyphosphate. 

The only after-treatment that is necessary is that comprehended in a 
thoroughly clean condition of the mouth, secured by careful brushing and 
the frequent use of antiseptic solutions. The splint may be permitted to 
remain in position for a period ranging from four to twelve weeks. 

Method of Union.— The union which takes place between the alve- 
olus and a fresh tooth in which the pericementum is intact over the whole 
surface of the root would seem to be by a normal process, like that which 
takes place between these tissues in a tooth which has been dislocated by 
accident and immediately replanted. 

In those cases, however, in which the pericementum has been removed 
in part by shortening of the root or by disease the union seems in some 
cases to be bony, in others fibrous. 

Mitscherlich transplanted a tooth in a dog, and after six weeks ex- 
amined it, and found that a considerable portion of the pericementum had 
disappeared, that resorption had taken place at several locations, followed 
by calcification of the osteoclasts and the formation of new tissue within 
the spaces or cavities formed by the resorptive process. This new-formed 
tissue was continuous with the bone of the alveolus, and held the tooth 
firmly within its alveolus. 

The notion that has been held by some operators that the pericementum 
of the tooth after it has been extracted for some considerable time and 
had become dried and dead was after transplantation revivified has no 
foundation in fact, and is directly opposed to all physiologic law. The 
attachment which occurs between such teeth and the alveolus is, in all 
probability, a semi-mechanical one, such as was demonstrated by Mitscher- 
lich in his experiment upon the dog. 

Prognosis. — Resorption of the roots of transplanted teeth usually occurs 
at an earlier or later period, ranging from a few months to four or five 
years, although in exceptional cases they have remained successful for a 
considerably longer period ; the late Dr. Morrison reported cases which 
were successful after eleven years. 

IMPLANTATION OF TEETH. 

Definition. — Implantation (Latin, implantatio, from in, in, and plan- 
tare, to set), the act of setting in. Applied to surgery it may be the 
engrafting of epidermis from the skin of one person upon the body of 
another, the surgical repair of a wounded intestine by uniting the divided 
ends, or the setting or transplanting of a tooth taken from the jaw of 
one person and inserted into an artificial alveolus made in the jaw of 
another. 

Implantation of teeth is an operation of modern times, suggested by 
Dr. Younger, of San Francisco, California, and when first introduced 
attracted considerable attention from the profession. Many operations 
were made with little regard to the physical condition of the persons 
operated upon or to the hygienic conditions of the mouth. Teeth were 



TRANSPLANTATION AND IMPLANTATION OP THE TEETH. 497 

implanted for persons suffering with syphilis, tuberculosis, and other con- 
stitutional diseases, and certain vicious habits like alcoholic intemperance, 
which, have a tendency to lower the recuperative powers of the tissues and 
favor the suppurative process. Consequently there were very many more 
failures than would in all probability have occurred had the cases selected 
for the operation been more carefully chosen. 

The only persons upon whom the operation should be performed are 
those who are in vigorous health, whose occupations do not call for an un- 
usual expenditure of nerve force, and who are accustomed to keeping their 
mouths in the very best hygienic condition. 

Requirements for the Operation. — The successful performance of 
the operation of implantation requires upon the part of the operator an 
intimate knowledge of the anatomy of the parts involved and their rela- 
tionship to other parts. It must be constantly borne in mind that after 
resorption of the alveolar process has taken place the depth of the bone 
is very much less than before the tooth had been extracted. In some cases 
the bone which intervenes between the apices of the roots and the nasal 
fossa or the antrum of Highmore is extremely thin, often not more than 
one-fourth to three-eighths of an inch in thickness, while in extreme cases 
it rarely exceeds half an inch in thickness. 

It is necessary, therefore, to exercise great care, in forming the artificial 
alveolus in the upper jaw, not to penetrate the nasal fossa or the antrum 
of Highmore, or to encroach upon the anterior palatine canal, which carries 
the anterior palatine artery, vein, and nerve, when forming an alveolus for 
a central incisor. When resorption of the alveolar process has been very 
considerable, it is often exceedingly difficult to so form the artificial 
alveolus as to give the tooth its right position and inclination in the arch 
and preserve a bony wall for the labial surface of the alveolus. This diffi- 
culty is more often encountered in the region of the central and lateral 
incisors than in that of the cuspids. 

Should the operator be so unfortunate as to penetrate the nasal fossa or 
the maxillary sinus, extreme care must be exercised not to infect the sinus. 
To guard against infection the artificial alveolus should be immediately 
plugged with a single strip of antiseptic gauze, which should remain until 
the tooth is ready to be inserted into its new alveolus. 

To guard against the possibility of the apex of the tooth passing into 
the nasal fossa or the antrum under these circumstances, the depth of the 
bony socket should be measured and the root shortened to correspond with 
its depth. 

The preparation of the tooth selected for implantation should be the 
same as for a tooth which is to be replanted or transplanted. 

The next step in the preparation for the operation is the construction 
of a metal splint to secure the tooth in position while union is taking 
place. This is done by taking an impression of the space to be occupied 
by the implanted tooth and the teeth upon either side of it. A plaster 
cast is made from this impression, a bite is taken, and the whole placed in 
an articulator. A suitable-sized socket is then drilled in the plaster cast, 
the root of the tooth adjusted therein, and the proper occlusion secured. 

32 



498 



OPERATIVE DENTISTRY. 



Fig. 578. 



■ £ 

Circular knives. 



3 



From the plaster cast, with the tooth retained in it, a die is made and the 
metal splint swaged over it. 

The tooth is then thoroughly cleansed and placed in a suitable disin- 
fecting solution, 1 to 1000 bichloride, or a saturated boric acid solution, 
and kept at a temperature of 100° to 110° F. until the artificial alveolus 
has been made in the jaw. 

Method of Operation. — The first step in the operation is to make an 
incision in the gum-tissue down to the bone. The form of this incision 
will depend largely upon the individual preference of 
the operator, the main object being to conserve as 
much of the firm tissue as possible. Some operators 
employ a circular incision made with the Eollin circu- 
lar knives (Fig. 578), others prefer a crucial incision 
(X), which makes four flaps ; others an incision in 
form of the letter H, which makes two flaps ; while 
still others prefer to employ a U-like or staple-like 
( LI ) incision, which forms a single flap. 

In the X or crucial incision the centre of the cross 
should correspond with the centre of the alveolar 
border, and the flaps are to be turned back out of the 
way of the instruments which are used to form the 
socket in the bone. 

In the letter H incision the upright lines of the 
incision are made across the alveolar border, close to the approximal sur- 
faces of the teeth upon the mesial and distal sides of the space to be filled 
by the implanted tooth, while the bar or horizontal incision should con- 
nect the upright incisions through the centre of the alveolar border. 

In the U-like or staple-like (U) incision the upright incisions are 
made across the alveolar border, close to the approximating teeth, while 
the curved or the straight incision made to connect the upright incisions 
are to be made at the lingual border of the alveolus. 

The incisions having been made, the next step in the operation is to lift 
the flaps from the bone, and in doing this care should be taken to get be- 
neath the periosteum, so that this membrane will be left adherent to the 
gum-tissue, as by so doing the periosteal layer of the flaps will, when it 
comes in contact with the root of the implanted tooth, assist in forming a 
new alveolar border. Delicate periosteotomes for this purpose may be 
made from selected enamel chisels by rounding the cutting edges. 

The flaps, having been lifted from the bone, should be held out of the 
way by a delicate spring tenaculum-speculum during the forming of the 
new alveolus. The greatest care should be taken not to bruise the edges 
of the flaps, otherwise inflammation and sloughing of the borders or of the 
entire flap may follow. 

Various instruments have been suggested for the purpose of forming 
the socket in the bone. The first instruments made for this purpose were 
the Younger trephines ; these have since been improved by Dr. W. W. 
Walker, of New York, and are now made with a set-screw collar which 
slides upon the shaft of the instrument (Fig. 579), and can be set at any 



TRANSPLANTATION AND IMPLANTATION OF THE TEETH. 



499 



point to correspond with the desired depth of the alveolus. Instruments 
of this character, however, need to be supplemented with others which 
cut upon the side, as with the trephine alone the alveolus cannot be prop- 
erly shaped or the core removed. 

The reamers designed by Dr. Younger (Fig. 580) for this purpose have 
a serious disadvantage in that they are inclined to clog. The spiral 
knives of Dr. Eollin (Fig. 581) are a decided improvement over the 
Younger reamers, in that they are not so liable to clog and cut much 
more rapidly. The combination drill and reamer instruments (Fig. 582) 
of Dr. Ottolengui, of New York, are the best of this series of instruments, 
in that they cut very freely and rapidly, do not clog, and are provided 
with a safety collar that can be set to suit any depth of alveolus that it 
may be desired to make. 

Fig. 581. 



Fig. 579. 

© oooO 




Younger- Walker trephines 



The Ottofy spiral crib-knife is also a valuable instrument, as it cuts 
with great rapidity and does not clog. The spiral osteotomes of Dr. M. H. 
Oyer, of Philadelphia, are designed for the same purpose, and are the 
most rapid-cutting instrument of the series, and if permitted to run freely 
they do not clog. Long-shanked, coarse-cut engine-burs are also useful 
for making any slight changes that may be required in the shape or depth 
of the alveolus. 

During the process of forming the alveolus the parts should be fre- 
quently irrigated with an antiseptic solution, preferably a saturated solu- 
tion of boric acid in water or the Thiersch solution. After the proper 
depth has been reached, and during the progress of shaping the alveolus, 
the tooth should from- time to time be inserted until the proper adjust- 
ment to the socket and the position in the arch has been secured. Another 
important feature of the operation is to secure a proper occlusion, but it is 
better to have the tooth a trifle too short than by ever so small a fraction 
too long, for if the pressure of the jaws comes entirely upon the implanted 
tooth, inilammatioii is liable to follow as a consequence of the mechanical 
irritation. 



500 OPEEATIVE DENTISTRY. 

As soon as hemorrhage has ceased, the mouth and the socket should be 
irrigated with a 1 to 1000 mercuric bichloride solution, the tooth washed 
in the same solution and then placed in position, the parts dried, and the 
splint cemented in place. As soon as the cement has set the surplus should 
be removed, the parts again irrigated with the bichloride solution, and the 
edges of the gum flap nicely adjusted to the cervix of the tooth. If the 
corners of the flaps are inclined to fall away — evert — from the cervix, a 
suture of prepared horse-hair may be passed through each labial and lin- 
gual corner and tied between the teeth. The sutures should be removed 
on the third or fourth day. The after-treatment should consist of frequent 
irrigations of the mouth with antiseptic solutions and careful removal of 
food debris from around the seat of the operation, and such other means as 
will secure the most perfect hygienic condition of the mouth. 

Prognosis. — Implanted teeth, like transplanted teeth, sooner or later 
are lost by resorption of their roots. Many cases of implanted teeth, how- 
ever, never formed any kind of union as the result of suppuration which 
immediately followed the operation ; others formed a slight attachment to 
the alveolus and loosened after a few weeks or months, and dropped out or 
were removed with the fingers ; still others became firmly attached, and 
remained firm for a year or two, when they became loose from resorption 
of their roots, and on account of intense irritation had to be extracted ; 
while a very limited number have done good service for periods ranging 
from three to ten years. On the whole, then, the operation is not one to 
be recommended except under the most favorable circumstances, — viz., 
when a freshly extracted healthy tooth can be inserted into the newly 
formed alveolus of a youth or young adult of the most perfect health and 
constitution. 



CHAPTER XXXII, 

DISLOCATION OF THE TEETH. 

Definition. — Dislocation, from the Latin dislocatus, to put out of 
place ; luxation, from the Latin luxatus, to put out of joint. A dislocation 
or luxation is a displacement of a part from its normal situation. 

Two or more bones whose articular surfaces have lost, wholly or in part, 
their natural relationship are said to be dislocated or luxated, and the 
condition would be termed a dislocation or luxation. 

A tooth which is partially or completely dislodged from its alveolus is 
said to be dislocated or luxated. 

Dislocations of the teeth are of two classes, — viz., partial and complete. 

A partial dislocation is one in which the tooth is loosened and partially 
dislodged from its normal attachments and position. 

A complete dislocation is one in which the tooth is completely or wholly 
dislodged from its normal attachment and position. 

Dislocations of the teeth are always the result of some form of external 
violence, such as direct blows or falls upon the teeth, accidental dislodge- 
ment of a contiguous tooth in the operation of extraction, or violence ap- 
plied indirectly, as a blow or fall upon the chin or the side of the face. 
Injuries which cause fractures of the jaws almost invariably produce dis- 
location of one or more teeth at the line of the fracture. 

In partial dislocations the tooth may be either dislodged in an outward 
direction or driven into the alveolus to a greater or less extent, while in 
complete dislocations the tooth may be entirely dislodged outwardly, or 
completely driven through the alveolus into the nose or the antrum of High- 
more. 

Treatment. — In the treatment of partial outward dislocations of the 
teeth the parts should be thoroughly irrigated with antiseptic solutions, 
cleansed from all blood-clots and foreign substances or loose pieces of frac- 
tured alveolar process, the teeth forced back into their normal position 
and supported by ligatures of silk or wire, or firmly held in place with a 
vulcanite or metal splint cemented to the adjoining teeth, and allowed to 
remain until union with the alveolar tissues has taken place. This result 
may be confidently expected in from one week to ten days, provided sup- 
puration does not supervene. To guard against the establishment of 
suppuration the mouth and the injured parts should be frequently irrigated 
with antiseptic solutions. 

In the treatment of those cases in which the tooth is partially driven 
through the alveolus, the crown of the tooth should be -grasped by a pair 
of suitable forceps and drawn down to its normal position. In a majority 
of these cases, however, it will be found that the attachment of the tooth 
to the alveolar wails has been entirely broken up, so that when force is 
applied to draw the tooth into position it will be completely dislocated. 

501 



502 OPEEATIVE DENTISTRY. 

If the tooth still retains a partial attachment to the alveolus, it should be 
treated as just described, and held in position by means of a ligature or a 
splint. 

As a rule, teeth which have been dislocated even partially have suffered 
rupture of the nerve and blood-vessels at the apical foramen, so that in a 
short time, ranging from ten days to a few weeks, the tooth gives evidences 
of containing a devitalized pulp, and should therefore be ojjened, the pulp 
extirpated, and the pulp-canal filled. 

Occasionally, however, if the tooth is immediately replaced in its 
normal jDOsition, union of the blood-vessels and the nerve may take place. 
Numerous cases of this character have been reported from time to time in 
dental text-books and periodical literature. The writer has had two such 
cases in his own practice, — one a lower second bicuspid, which responded 
to the usual tests of heat, cold, and the electric current twelve years after- 
wards, and the other a second lower molar, which was vital two years 
afterwards. These cases were both of them in young women of vigorous 
health and good family history. These results are more likely to follow 
such accidents occurring in the young, particularly if they happen during 
the formative period of the teeth, than if they occur at any time there- 
after. In tubercular and syphilitic individuals replantation of dislocated 
teeth is rarely successful, as injuries of even a trivial nature are prone to 
inflammation and suppuration. 

Teeth which have been completely dislocated outwardly should, before 
being replanted, have the pulp extirpated and the pulp-canal filled with 
gutta-percha, and the apical foramen and the crown-cavity filled with gold. 
These operations should be performed under the strictest antiseptic pre- 
cautions, as suggested in the section of the chapter on Dento- Alveolar 
Abscess devoted to replantation of the teeth. 

Injuries which cause dislocations by driving the teeth into or through 
their alveoli and into the nasal cavity or the antrum of Highmore usually 
cause more or less severe fracture and comminution of the alveolar process 
and superior maxillary bones. Such injuries are generally the result of 
falls from a considerable height, as from a building, or being thrown from 
a horse or a bicycle, or from some crushing injury like railway accidents, 
the overturning of a carriage upon the occupant, or an elevator accident 
whereby the head is caught between the moving car and the floor. But 
even under such circumstances it is possible in many cases to bring the 
fractured bones into normal apposition and to successfully replant the 
teeth.* It is surprising how readily reunion will take place in these cases, 
and what good cosmetic results may be obtained by the application of a 
little skill and patient, intelligent, after-treatment. 

The first thing to be done in these cases after the mouth has been 
cleansed of blood-clots and rendered as nearly aseptic as the circumstances 
will permit, by the liberal use of antiseptic solutions, is to search for and 
remove all of those teeth which have been driven into their alveoli or into 
the nasal cavity or the maxillary sinus. In nearly all of these cases it will 

* Marshall's Injuries and Surgical Diseases of the Face, Mouth, and Jaws, 1897. 



DISLOCATION OF THE TEETH. 



503 



Torsion forceps. 



be found that the alveolar process is split open, the external plate of the 
process being the one which is usually fractured and forced outward. 

This condition very materially assists in the effort to find and remove 
the buried teeth. The teeth so dislocated are often completely buried out 
of sight, or are lost in the 

antrum. Diligent search must 583- 

be made for all missing teeth ; " r;t '^ ;: ^^ ^^^^mmm^k 
and if one has been driven ^^^^^^^s^ 

into the antrum, this sinus 
must be opened by enlarging 
the alveolus of the tooth, and the tooth removed. This is sometimes a 
difficult problem ; but if the opening be made sufficiently large, the tooth 
can be grasped by a pair of torsion forceps (Fig. 583), or bullet forceps 
(Fig. 584), and removed ; if the forceps will not retain their grasp upon 
the tooth, it is possible to remove it with a wire-loop snare (Fig. 585) or 
an ecraseur such as is used for the removal of nasal polypi. 

After the completely dislocated teeth have been extracted, all loose 

fragments of bone should be re- 
moved from between the alveolar 
plates and the bones brought 
into correct apposition. 

In order to retain them in 

their normal position it may be 

necessary to pass silver sutures 

through the alveolar plates by 

first drilling holes for their reception at suitable locations. Lead buttons 

may be used at the termini of the sutures to keep them from cutting into 

the soft tissues. 

After the fractured bones have been adjusted the alveoli should be 
cleansed from blood-clots, and the teeth, which had been previously 
cleansed and placed in a tepid three per cent, solution of carbolic acid or a 



Fig. 584. 




Bullet forceps. 



Fig. 585. 




(iiKH'h's double canula snare. 



1 to 1000 bichloride solution, may now be replanted in their normal position 
and retained by means of ligatures. 

The first part of the operation- would of necessity be of such a painful 
nature that a general anaesthetic would be required, and the length of time 
that would be necessary to remove the pulps from the teeth and properly 
fill them would make it impossible to do this while the patient was under 
the anaesthetic. While, upon the other hand, the chances of reunion of 



504 OPEEATIVE DENTISTRY. 

the replanted teeth with their alveoli is much greater if the teeth are 
replaced within an hour or two after the injury which has dislocated them. 
The pulp-canals of such teeth may be opened later, and such treatment 
instituted as the conditions indicate. 

"It is interesting in this connection to note the time required to 
produce death in the various tissues of the body by the arrestation of the 
blood-current. The period varies in the different tissues. Brain-tissue, 
renal epithelium, and intestinal epithelium die in two hours. Skin, bone, 
and connective tissue continue to live over twelve hours." (Cohnheim.) 
Tissues which exercise special functions die more quickly than those which 
do not exercise such functions. These facts should govern all operations 
for the transplantation or replantation of teeth. Success is more likely to 
follow the effort of transplanting and replanting of teeth if the operation 
is completed within an hour or two after the extraction of the tooth.* 

Sometimes a single anterior tooth will be driven through its alveolus 
and into the cancellated tissues beyond, penetrating the floor of the nasal 
cavity, without fracturing the alveolar process. Under such circumstances 
the tooth will be so firmly fixed as to require considerable force to dis- 
lodge it. The writer saw a case of this character at one time in which a 
central incisor was driven completely out of sight, and the tooth was sup- 
posed by the patient to have been knocked out and lost. The case was so 
diagnosed, also, by the family physician and the dentist. Careful examina- 
tion with the probe, however, discovered the crown of the tooth about a 
third of an inch beyond the border of the alveolus, which was, after con- 
siderable difficulty, extracted with a pair of very thin-beaked, straight 
root-forceps. The tooth, after the removal of the pulp and appropriately 
filling the canal, apical foramen, and crown-cavity, was replanted and 
made a good union. 

Prognosis. — The prognosis of replanted teeth under the conditions 
just mentioned is exceptionally good in all healthy subjects. The period 
of the future usefulness of such teeth may be confidently expected to ex- 
tend over many years. In some of them, however, there is, after a vary- 
ing period, a tendency to resorption of the root, and ultimate loss of the 
tooth. 

* Marshall, Injuries and Surgical Diseases of the Face, Mouth, and Jaws, p. 98. 



CHAPTER XXXIII. 

FEACTUEES OF THE TEETH. 

Definition. — Fracture (from the Latin fractura, a break), the breaking 
of a bone or a tooth, either by external violence or other form of injury. 

Fractures of the teeth, like fractures of the bones, may be divided into 
three classes, — viz., simple, compound, and comminuted. 

Simple fractures are those which involve the hard structures of the 
crown and do not injure the pulp. 

Compound fractures are those in which the fracture is of such extent 
as to involve the pulp in any portion of the crown or root. 

Comminuted fractures are those in which the tooth is broken, crushed, 
or split into many fragments. 

Simple fractures may be of such a nature as to involve only a very 
small portion of the enamel, or they may be so extensive as to involve a 
large section of the crown and nearly expose the pulp. 

The incisors, from their exposed position, are more liable to fractures 
of all classes than the bicuspids or the molars, while the cuspids, from 
their peculiar form and great strength, are the least liable to such acci- 
dents, though they are by no means entirely exempt. 

The causes which produce simple fractures of the anterior teeth are 
grinding the teeth and incising such substances as threads, which chip the 
edges of the enamel, or blows and falls, which cause fractures of larger 
portions of enamel and dentin, while such fractures occurring in the 
bicuspids and molars are usually produced by biting hard substances or 
by blows and falls upon the chin, which drive the jaws together and split 
off a cusp or produce more serious injury. 

Slight fractures confined to the enamel need only to be made smooth 
with files, stones, or disks, and then polished with pumice. When larger 
sections of the crown are broken away, the lost portions should be restored 
with gold or porcelain. It must not be forgotten, however, that injuries 
which expose the dentin often leave this portion of the tooth extremely 
sensitive, and not infrequently cause hyperemia and death of the pulp as 
a result of the shock induced by the injury, or from thermal impressions 
upon the exposed fibrillse. 

The application of escharotics to the exposed dentin for the purpose 
of obtunding its hypersensitiveness is to be deprecated, for the reason that 
such applications often cause severe irritation and hyperemia of the pulp, 
which may result in devitalization. For these reasons it is better to treat 
such cases by covering the exposed dentin with gutta-percha or zinc oxy- 
phosphate cement and wait for developments. If after a month or six 
weeks the tooth remains vital and is not hypersensitive to thermal 
changes, a permanent restoration of the lost portion with gold or porcelain 
may be undertaken. 

505 



506 OPERATIVE DENTISTEY. 

Compound fractures are generally the result of severe injuries, such as 
blows or falls, which bring the anterior teeth in contact with some hard 
substance, causing fracture of the crown and exposing the pulp, or which 
drives the jaws forcibly together and splits the crown of a bicuspid or a 
molar through the pulp-chamber, or carries away a large section of the 
crown, exposing the pulp. The fragments in fractures which occur through 
the pulp-chamber, sometimes in such close apposition that the most careful 
examination is necessary to detect the character of the injury. The writer 
has seen several cases in which a persistent odontalgia was finally discov- 
ered to be due to such a cause. 

Bicuspids and molars which have been filled upon the mesio-disto- 
morsal surfaces are quite prone to be fractured through the pulp- chamber 
or to have a cusp split off while chewing very hard food, or when acci- 
dentally biting upon some foreign substance hidden in the food, like a 
piece of bone, a shot, a piece of shell or stone. 

Compound fractures of the anterior teeth are usually either transverse 
or oblique, while in the bicuspids and molars the line of fracture is gen- 
erally oblique or longitudinal, following the line of the pulp-chamber. 

Oblique fractures are, however, the most common in both the bicuspids 
and molars. In bicuspids which have two roots, and in the lower molars, 
the fracture in the crown may extend in a longitudinal direction, separa- 
ting the roots, while in the superior molars it usually separates the palatine 
from the buccal roots. Occasionally the root of an anterior tooth may be 
fractured transversely at some distance beneath the gum. 

Treatment. — Fractures, either oblique or transverse, which open the 
pulp- chamber, but do not extend beneath the gum, should be treated with 
a view to finally setting an artificial crown upon the remaining firm root, 
but in those cases in which the fracture follows the pulp-canal, or in which 
the root is otherwise seriously involved, extraction is the only treatment to 
be recommended. 

An exposed pulp should be extirpated at once in order to give relief 
from the severe pain. This should be done under a general anesthetic. 

In devitalized superior molars and in double-rooted superior bicuspids 
which have been fractured on a line with the pulp- chamber separating the 
roots it is sometimes possible, after ligating the fragments together with a 
stout silk ligature, to secure the fractured parts and retain them in a nor- 
mal position by drilling a hole through the crown bucco-lingually, well 
towards the gum, counter- sinking the hole upon both the buccal and lin- 
gual surfaces and inserting a bolt with a screw-nut made of eighteen-carat 
gold, filling over the head of the bolt and the nut with gold or with zinc 
oxyphosphate or amalgam, and replacing any fillings in the line of the 
fracture through the crown with cement or amalgam, and in very rare 
instances with gold. 

Another method is to fit a gold or platinum band to the outer circum- 
ference of the tooth, and retain it in position with zinc oxyphosphate. 
This method is particularly applicable to the lower molars which have been 
so fractured as to separate the mesial and distal roots. 

Still another method may sometimes be adopted with success in those 



FRACTURES OF THE TEETH. 507 

cases in which the crown is considerably decayed or contains large fillings, 
— viz., to set a gold shell -crown. This may be accomplished by first se- 
curing the fragments in proper apposition by the aid of a piece of fine iron 
binding wire passed around the cervix of the tooth and twisted tightly. 
The crown may then be cut to proper shape and length, measured, the 
band fitted, and the crown made and finished by the usual methods. 

Comminuted fractures are always the result of severe injury from con- 
cussion or some heavy crushing force, which usually so comminutes the 
crown and root, together with the alveolar walls, as to destroy the integ- 
rity of the tooth and make it necessary to remove the crushed fragments. 
Occasionally the crown only will be comminuted and the root left intact. 
Under such circumstances the root may be conserved and an artificial 
crown set upon it. 

Spontaneous fracture sometimes occurs in a tooth which contains a de- 
vitalized pulp or a very large metal filling without any seemingly apparent 
cause. It has been suggested by some writers that in the former the tooth 
was fractured by internal pressure from the evolution of gas in a closed 
pulp -cavity as the result of the decomposition of the pulp ; while in the 
latter it was due to the expansion of the metal filling induced by thermal 
changes. Tomes suggests that it may be due sometimes to a calcified pulp, 
which acts as an internal wedge when a distorting force is brought to bear 
upon the tooth. It is possible that such forces as have been mentioned 
may produce these fractures, but the writer is inclined to the opinion that 
in each of these conditions the fracture is often due to some unusual force 
applied to the tooth, either in masticating or in grinding the teeth together 
while the individnal is asleep. A tooth with a devitalized .pulp has usu- 
ally been weakened by a cavity of decay, while a tooth which contains a 
large metal filling is also in a weakened condition, and therefore less able 
to withstand any undue strain that might be placed upon it. 

Union of Fractured Teeth. — As a rule, teeth which have been frac- 
tured do not become reunited. This is no doubt due to the fact that the 
dentin has no blood circulation, and that the cementum has but few blood- 
vessels as compared with bone-tissue, and yet there are several instances 
on record in which union of fractured teeth has undoubtedly taken place. 
Fractured bones almost universally reunite, and but for the character of 
the dental tissues the same result might be confidently expected in the 
teeth. The union which has taken place in the few instances recorded 
seems to be due to the active agency of the pericementum, which has 
thrown out new osseous (cement) material around the fracture, just as is 
done by the periosteum in fractured bones. It is possible that the pulp 
in some rare instances may take part in forming the reunion. Reunion of 
fractured teeth is much more likely to result if the fracture takes place 
during the formative period of the root, or soon thereafter, than it is if the 
fracture occurs after adult life is reached. The probability of reunion 
taking place in a fractured tooth is increasingly greater as the line of 
fracture nears the apical third of the root. 

The conditions which are necessary to promote reunion in the fractured 
root of a tooth are correct apposition and immobility of the fractured 



508 OPERATIVE DENTISTRY. 

parts, the vitality of the pulp, and a healthy condition of the pericemen- 
tum. Eeunion will fail if the fractured parts are separated by any appre- 
ciable space, or if they are in constant motion, or the pulp dies and be- 
comes decomposed, as septic conditions are established at the site of the 
injury, and by that means the reparative process is arrested or entirely 
prevented, and if the pericementum is not in a fairly healthy condition 
the reparative process cannot be established, as this is the most important 
structure involved in this process. 

Wedl* is of the opinion that the pulp takes some part in the process of 
reunion of fractured teeth, and he figures two reunited fragments in which 
a deposition of reparative dentin took place, — one was a human superior bi- 
cuspid, the other an incisor of an antelope. Tomes f mentions two cases, one 
a human molar in which union of the fragments had been secured by the 
formation of new cement-tissue around the fracture. The other was a tusk 
of a hippopotamus in which the fragments had been considerably sepa- 
rated, but which had been perfectly reunited with new-formed cementum. 

Professor Owen mentions a similar case in the tusk of a hippopot- 
amus, x 

Hyatt describes a specimen of reunited fracture of a central incisor to 
be found in the Anafomical Museum of Breslau. 

Heider mentions a specimen contained in his private collection of a 
perfectly reunited fracture in a superior bicuspid. 

Hohl records fourteen eases found in man and the lower animals, eight 
of which were human, seven being incisors and one a superior bicuspid. 
One remarkable case recorded by Hohl in which reunion was perfect is 
described as follows : 

' ' Professor V. , as he was about entering a railway car, fell, striking his 
mouth upon the sharp edge of an iron step in such a way that the right 
superior central incisor was fractured lengthwise. The fracture separated 
the tooth in the middle of the crown so completely that the two fragments 
diverged from each other, and could be moved back and forth. After the 
lapse of fourteen days, during which time the intense pain entirely pre- 
vented the use of the fractured tooth, a more comfortable condition en- 
sued, and in a few weeks more the tooth completely resumed its normal 
functions. The two halves of the tooth became firmly adherent to one 
another, and the line of union was indicated by merely a fine line with a 
slightly brownish tinge." § 

The late Sir E. Saunders has described an incisor belonging to his 
private collection, which shows a perfectly reunited fracture which had 
occurred at the junction of the middle and apical thirds of the root. 
Belisario also reports a case of fracture of a tooth with reunion of the 
severed fragments. Bennett describes a fractured incisor tooth in which 
the fragments were apparently considerably displaced and had become 
reunited in their displaced position. 

* WedPs Dental Pathology. f Tomes' s Dental Surgery. 

t Odontography. § American System of Dentistry. 



CHAPTER XXXIV. 

RESORPTION OF THE ROOTS OF PERMANENT TEETH. 

Definition. — Resorption (Latin, resorptio, from re, again, and sobere, to 
absorb), the process whereby formed tissue is converted into its original 
elements by the action of specialized cells and taken into the blood-cur- 
rent by absorption. 

Bone is resorbed through the action of the osteoclast cells. The roots 
of the permanent teeth are resorbed by a similar process, and is analogous 
to that observed to take place in the roots of the deciduous teeth prior to 
their exuviation. The former, however, is a pathologic condition, while 
the latter is physiologic. 

The resorption of dental tissues other than that appearing in connec- 
tion with the removal of the roots of the deciduous teeth prior to the 
eruption of the permanent teeth must therefore be considered a pathologic 
process. 

Causes. — The principal predisposing causes of resorption of the roots of 
the permanent teeth are of two classes, — one which is dependent upon con- 
ditions associated with the tooth itself, and the other to conditions which 
are entirely foreign to the tooth. 

In the first class of causes are death of the pulp, necrosis of portions 
of the pericementum, and functional disuse of the tooth due to the loss of 
its antagonist. In the second class are irritation from an erupting but 
malposed tooth, as, for instance, a third molar, which presses against the 
distal root of a second molar, or the presence of a foreign body in con- 
tact with the root. 

The process of resorption is much more rapid in pulpless teeth and in 
those in which portions of the pericementum have been destroyed by a 
suppurative inflammation, such as would attend dento-alveolar abscess. 
It may be stated as a general fact that the progress of the disease is much 
more rapid in tissues whose blood-supply or nutrition have been reduced 
or largely cut off, while, on the other hand, the greater the blood-supply 
coming to the part so attacked the more successfully will it resist the de- 
structive process. In other words, vital resistance plays an important 
part in determining the rapidity with which the tissues are dissolved by 
this process. 

When the process attacks a tooth with a vital pulp, its action is more and 
more retarded as it approaches the pulp, and in some of these cases the 
cementum and dentin have been removed, leaving only a thin tube-like pro- 
tection of dentin surrounding the pulp. In those cases of resorption caused 
by an advancing rnalposed tooth, it will be noticed that at the point of con- 
tact only will the process be active, and the form of the excavation made 
in the root of the tooth attacked by the resorptive process will correspond 
to that portion of the surface of the tooth which is advancing towards it. 

509 



510 OPERATIVE DENTISTRY. 

There is never, however, absolute contact of these surfaces ; they are 
always separated by a mass of multinucleated cells which are doubtless 
modified osteoclasts. The process of resorption sometimes extends to 
such depth as to expose the pulp in the root of the tooth, and thus cause a 
severe and sometimes obscure odontalgia and later on a dento-alveolar 
abscess. 

Exciting Causes. — Contiuued irritation of almost any form may in- 
augurate the resorptive process. Among the more common of the exciting 
causes may be mentioned chronic septic pericementitis, chronic dento- 
alveolar abscess, a nerve broach broken off in the pulp-canal and project- 
ing through -the apical foramen, the presence of a root-canal filling which 
projects into the apical space, or a severe injury, as from a blow upon the 
tooth. In certain cases, however, the resorptive process seems to have no 
discoverable cause whatever. 

Pathology. — The macroscopic appearances of the roots of teeth which 
are being resorbed present such a wide difference that it may be safely said 
that the process rarely attacks any two teeth alike. This will be noticed 
by reference to the illustrations. Fig. 586 shows the result of a chronic 
irritation at the apex of a vital superior central incisor. In this case the 
resorption has produced a smooth, regular, and rounded shortening of the 
root. Fig. 587 illustrates the same condition occurring at the apices of 
roots of a devitalized superior molar. Fig. 588 represents two vital superior 
central incisors in which the process of absorption was most active upon the 
mesial surface, extending from apex to cervix. The writer is indebted to 
Dr. Wright, of Chicago, for these latter specimens loaned from his private 
collection. The surfaces which have been attacked in these teeth present 
deep, uneven, bay-like excavations and numerous small, rounded open- 
ings, which give them the appearance of being worm-eaten. In Fig. 589 
the process is shown to have scooped a large, smooth excavation in a 
devitalized superior bicuspid, well up towards the apex, leaving sharp, 
clean-cut edges. Sometimes the whole root is absorbed, but this is rare. 
Fig. 590 shows a devitalized inferior bicuspid in which the disease has 
extended much farther. This tooth had been crowned with gold several 
years before the writer saw the case, and no other history could be ob- 
tained. In this case the resorptive process had extended into the crown 
upon one side. Fig. 591, a devitalized central incisor, has lost about one- 
half of its root ; the disease evidently began on the labial aspect of the 
root near the apex. In this case the dentin has been dissolved much more 
readily than the cementum, thus causing a very deep depression. 

Fig. 592 shows a devitalized superior central incisor in which the process 
of resorption has gone considerably farther, and has removed almost the 
entire root and formed a deep depression in the crown. 

Fig. 593 was a vital superior cuspid which has a small depression or 
cup-shaped cavity upon the labial surface of the root near the middle, and 
shows a very early stage in the resorptive process. 

Fig. 594 was another vital superior cuspid in which the disease began 
at the apex and has destroyed the upper half of the root. The peculiarity 
of this case lies in the fact that the disease has hollowed out the root 








Fig. 594. 

OFIG. 595. 
□ 




•/r. ■ 



Wfk 




Fig. 597.— Osteoclasts, producing resorption of the root of a tooth. X 45. 




lasts, producing resorption of the root of a tooth. 



RESORPTION OF THE ROOTS OF PERMANENT TEETH. 511 

almost to the cervix, leaving the outer shell of the cementum intact, and 
preserving a thin tube of dentin around the pulp. 

Fig. 595 represents the most interesting case of all. This is a lower sec- 
ond molar ; which had been extracted and replanted by a colleague for the 
cure of pyorrhoea alveolaris. The tooth was supported in position by a gold 
splint which encircled this tooth, the first molar, and the second bicuspid. 
The operation was made about two years previously. The tooth had been 
troublesome for more than a year, but, as there was no discharge of pus, 
it was thought best to allow it to remain. It finally caused irritation of 
the gum, and was therefore extracted. In this case the root and a large 
part of the dentin of the crown was entirely resorbed. The tissue, how- 
ever, was not removed in the same manner as in the resorption of the 
deciduous teeth, for in them the surface is left comparatively smooth, 
while in this case it is full of deep depressions and perforated with holes, 
as though worm-eaten. 

Fig. 596 shows a very peculiar form of resorption in a superior second 
molar, the result of inflammation of the pericementum induced by drilling 
through the side of the root in an effort to open the pulp-canal in the disto- 
buccal root. The probes are passed through the cavity of decay and the 
opening in the root made by the drill and through two other openings 
which were the result of the action of the cementoclasts. 

Upon microscopic examination of the surface which is being resorbed it 
is found to be covered with cup-shaped depressions of great minuteness, 
but there appears to be no alteration in the size or of the arrangement of 
the dentinal tubuli. These minute depressions are Howship's lacunar, and 
are doubtless formed by the action of multinucleated cells (Figs. 597 and 
598), the osteoclasts, or odontoclasts. 

The modus operandi by which the roots of the permanent teeth are re- 
sorbed seems to be identical with the process by which foreign substances 
composed of animal tissue, like ivory, catgut, silkworm gut, silk-ligatures, 
sponge, and decalcified chicken-bone drainage-tubes, etc., are resorbed 
when buried in the living animal tissues. The success of the process 
seems to depend upon the character of the inflammation, which must be 
of a degree that falls short of the suppurative process. This fact has been 
conclusively proved by numerous experiments (Billroth, Tomes, Krause, 
Kollicker, and others) with buried ligatures and other animal tissues. It 
was found that the establishment of the suppurative process immediately 
arrested resorption. This is doubtless due to the fact that the increase in 
the degree of the inflammatory process arrests the function of the resorp- 
tion cells or odontoclasts. 

Similar conditions are known to obtain in the exuviation of the de- 
ciduous teeth. Resorption in these teeth never progresses while suppura- 
tion exists about their roots. This is doubtless true also of the resorptive 
process in the roots of the permanent teeth. 

The examination of the roots of replanted, transplanted, and implanted 
teeth reveals the fact that where union or attachment has taken place with- 
out suppuration, and the teeth were subsequently extracted during some 
period soon after the operation, resorption must have taken place in various 



512 OPERATIVE DENTISTRY. 

locations, for excavations into the cementum are plainly seen, and these 
have been refilled by a deposition of new-formed cement tissue. Occasion- 
ally the alveolar tissues never become tolerant of these teeth, particularly 
the transplanted and the implanted ones, and under such circumstances 
the resorptive process is established and maintained uninterruptedly until 
the offending members, which act as foreign bodies, are expelled from the 
jaws. 

Symptoms and Diagnosis. — The symptoms are tenderness to per- 
cussion, a peculiar looseness of the tooth, which can be moved in a radius 
shorter than would be expected in a tooth of normal length ; later evidences 
of a mild pericementitis appear, and sometimes a slight discoloration of 
the tooth. On opening the pulp-canal the pulp is usually found to be de- 
vitalized, and upon passing a broach into the canal it encounters midway, 
or in the upper third of the root, a soft, fleshy mass of tissue. At other 
times the tooth may contain a vital pulp, and if it has been exposed by 
entering the canal with a drill, it must be devitalized ; but upon its re- 
moval and the exploration of the pulp-cavity the tooth will be found to 
have either undergone shortening of its root, or the probe will reveal the 
fact that the wall of the pulp-chamber has been invaded, and the cavity 
so made occupied with a mass of soft tissue. 

In vital teeth which are being thus resorbed the pulp will sometimes 
give evidence of being hypersemic by the marked increase in the normal 
heat sense of the tooth, and its intolerance to changes of even a few degrees 
in the temperature of substances coming in contact with it. 

In some of these cases the only symptom is one of discomfort, — not 
actual pain, but a discomfort which the patient will, perhaps, suggest does 
not seem likely to be relieved except by the extraction of the tooth. 

The diagnosis in the absence of positive signs may be made by exclusion. 
The Eontgen rays, however, if available, will give a positive diagnosis. 

Prognosis. — The prognosis, so far as the conservation of the tooth is 
concerned, is decidedly unfavorable. When once this process is established 
in a permanent tooth, it is sooner or later lost. If the diagnosis in these 
cases could be made early, and the source of irritation removed before the 
process of resorption had progressed to any considerable extent, it is possi- 
ble that the process might not only be arrested, but that a redeposition of 
tissue would take place and the tooth be preserved. But the difficulty lies 
in the fact that there seems to be no means of diagnosing the disease until 
it has gone so far as to make it impossible to save the tooth. 

Treatment. — Inasmuch as the only symptoms which are manifest in 
these cases are those of a mild pericementitis, every effort should be made 
to discover and remove, if possible, the cause or causes of irritation. If 
the tooth is one that has been devitalized or gives evidence of containing 
a dead pulp, the pulp-cavity should be opened and cleansed ; or the filling 
removed if one is found ; or broken instruments lodged in the pulp-chamber 
should be searched for and, if discovered, removed. But if, after treating 
the case antiseptically for a few days longer, there is no improvement in 
the conditions or abatement of the symptoms, the tooth should be extracted 
as the only means of giving relief. 



CHAPTEE XXXV. 

HYPERCEMENTOSIS. 

Definition. — The term hypercenientosis (from the Latin coementum, 
coarse stones, and hyper, the prefix used to denote superabundance) means 
an abnormal excess in growth — hypertrophy — of the cement-tissue of the 
tooth. 

Hypertrophy is an increase in the substance of a tissue or an organ, the 
result of an increase in or the multiplication of its elements, and brought 
about in such a manner that the structure of the hypertrophied tissue is 
not materially changed and does not differ essentially from the normal type. 

Hypercenientosis is therefore a simple increase in the volume of the 
elements which constitute the cement-tissue of the tooth, which retains in 
large measure the general character of the structure of the normal tissue. It 
may be circumscribed or diffuse, and may assume almost any size or shape. 

Causes. — The etiologic factors which produce this affection are of two 
classes, predisposing and exciting. 

The predisposing causes of hypercementosis are generally the result of 
those conditions, either constitutional or local, which induce a morbid 
activity in the cellular elements of the peridental membrane, especially 
those which increase its blood-supply beyond the normal. This condition 
may be produced by chronic inflammatory phenomena resulting from septic 
conditions of the pulp- canals of devitalized teeth or other cause of a low 
form of inflammation ; by malocclusion, or overuse of the tooth, causing 
congestion ; by the death of the pulp, which increases the blood-supply to 
the pericementum by diverting to it that x^ortion of blood which originally 
supplied the pulp ; by the selective action of such drugs as mercury, 
iodine, etc., which produce pericemental irritation and gingivitis ; by the 
irritation of mephitic gases contained in the tubuli of devitalized teeth 
percolating through the cementum and inducing chronic pericementitis, a 
condition which frequently occurs in teeth whose pulps have been removed 
and the canals properly filled ; while the presence of an excess of uric acid 
in the blood may also be classed as a predisposing cause, as it favors the 
deposition of the urates in the pericementum and thereby produces chronic 
irritation, which causes congestion of this membrane and, under favorable 
conditions, organization of the inflammatory exudates. 

The tendency of the pericementum to develop such excess of cement- 
tissue is undoubtedly in some instances constitutional, and is especially 
marked in certain individuals. This tendency seems in some cases to be 
inherited, and it is fairly good presumptive evidence that if the parents 
have developed the affection, the children will also suffer from it. 

Exciting Causes. — The exciting or active causes of the affection may 
be any form of irritation which excites a hyperamiic condition of the 
pericementum, such as excessive thermal changes, a severe strain upon the 

33 513 



514 OPERATIVE DENTISTRY. 

tooth, as in using great force to crush or incise a hard or tough substance, 
or the accidental biting upon some hard substance like a piece of bone, a 
shot, or a piece of stone ; or an injury from a blow or fall ; caries of the 
cervix ; the projecting edge of a filling ; the protrusion beyond the apical 
foramen of a gutta-percha or other filling-material, and cervical deposits 
of salivary calculus. 

Pathology. — Inasmuch as the formation of cementum is normally a 
more or less continuous process, beginning with the development of the 
root and the eruption of the tooth and ending only with its loss or the 
death of the individual, it becomes very difficult to draw the line at the 
point where cement formation ceases to be physiologic and assumes patho- 
logic features. An examination of a recently erupted tooth, one with its 
root developed to the normal length, shows the cementum to be composed 
of only a few concentric layers, while a tooth from an elderly person shows 
many such lamellae. But although the cementum is thin at the cervix and 
thick at the apex, the number of lamellae are about the same in all parts of 
the tissue. The formation of the cementum in lamellae indicates periods of 
functional activity and of rest upon the part of the cementoblasts (Figs. 
599 and 600). These lamellae closely follow the general outine of the dentin 
composing the root and form an even and smooth outer surface. In many 
pathologic specimens the surface presents a nodular appearance, or larger 
globular masses are formed at the apex or upon the side of the root, as 
seen in B and C, Fig. 601. In others, like the bicuspids and molars, the 
roots may be united, sometimes by simple fusion as shown at A, Fig. 601, 
at others by a considerable mass ; or the roots of two or more teeth may 
be joined together, as shown in D, Fig. 602. Fig. 602, which is made 
from a specimen kindly loaned the writer by Dr. Wright, of Chicago, 
shows a similar condition. 

Specimens of hypercementosis often show very great irregularity in 
the lamellation and in the surface of the dentin. At certain points deep 
excavations appear in the surface of the dentin, while other similarly ap- 
pearing excavations are filled with cement tissue which has no regular 
lamellated structure. Extensive areas of absorption upon one part of the 
root and large additions of new tissue upon another part may be observed 
in the same specimen. 

The character of the irritation which has stimulated the activity of 
the formative function of the cementoblasts is indicated by the surface of the 
new-formed cementum ; the smoother and more regularly globular its 
form (Fig. 603), the more continuously chronic has been the process, 
while if the surface is irregular or composed of numerous elevations and 
depressions, it is an evidence of irregularity in the character of the irri- 
tation, and indicates intermittent attacks of resorption and deposition. 

When such teeth are extracted the pericementum is found to be much 
thickened and abnormally vascular. Sometimes there will be found 
adherent to the irregular surface of the new-formed cementum certain 
flesh-like masses which remind one of the absorbent organ found attached 
to exuviating deciduous teeth. 

Examined microscopically, the new-formed cementum is shown to 




Fig. 599.— Transverse section of root of human tooth near the apex, showing dentin and cementum 
in hypercementosis. X 200. 




Fig. GOO.— Transverse section of root of human tooth near the apex, showing the dentin and the ce- 
mentum. X 175. 



• It* 






Fig. 604.— Transverse section of root of human molar, hypercementosis. X 96. 




Fig. 605.— Vertical section of root of human molar, hypercementosis. X 15. 




Fig. 606. — Transverse section of roots of human molar, near apex. X 75. 




ftf 









*% v.-" 



Fig. 607.— Transverse section of root of human tooth, hypercementosed, sh 
of the new-formed tissue. X 75. 



the irregular character 




Fig. 608. — Transverse section of alveolus and apex of root of abscessed human molar, showing resorption 
area partially refilled with a secondary formation of cementum. X 96. 




Enamel pearl 



Fig. 609. — Case of inostosis, with formation of a pearl-like globule resembling enamel. 




Fig. 610.— Transverse section of root of human tooth, showing case of inostosis. 




H YPERCEMENTOSIS. 515 

possess the characteristic general structure of cementum, but differing in 
the size, number, and arrangement of the lacunae and canaliculi, the thick- 
ness of the lamellae, and the distinctness of the incremental lines of 
Salter (Fig. 604). These differences depend in large measure upon the 
extent or thickness of the new-formed tissue. In normal cementum the thin 
laminae at the cervix of the tooth present no lacunae, but as the apex is 
approached they become more and more abundant, as do also the canal- 
iculi. Similar variations occur in the hypertrophied cement tissue (Fig. 
605). 

Vascular or medullary canals (Haversian canals) are exceptional in 
normal cementum, but they are frequently found in hypercementosis. 
The presence of these canals in the cementum is not, however, necessarily 
an evidence of pathologic conditions, for they are occasionally found in 
very thick cementum of normal teeth, particularly where two roots are 
joined together by cement tissue, as shown in Fig. 606. 

In hypercementosis having a smooth and regular surface the lamellae 
are fairly regular and the incremental lines of Salter generally well 
marked. The lacunae are more numerous and slightly larger than in 
normal cementum, but irregularly arranged and with the canaliculi 
running in a j;>eripheral direction, as seen in normal tissue. 

When the surface of the new tissue is irregular the character of the 
structure is more or less irregular. The lamellae are not so distinctly 
marked and the lacunae have a more irregular arrangement. These con- 
ditions are strikingly shown in Fig. 607. 

The density and texture of the various lamellae often differ considerably ; 
some seemingly are very perfectly calcified, with few or no lacunae, while 
in others calcification is quite imperfect and the lacunae are very numerous. 
In some cases lamination is not traceable in the new-formed tissue, which 
fact would indicate that the functional activity of the cementoblasts had 
been continuous, that there had been no periods of rest, no abatement in 
the stimulation or irritation. 

INOSTOSIS. 

A most curious condition is sometimes noticed in the structural arrange- 
ment of the new cement tissue, a condition which unmistakably indicates 
that lamellae already formed had been partially removed by resorption, 
and the excavations thus made afterwards filled by a redeposition of cement- 
tissue, as shown in Fig. 608. The process by which cement-tissue is re- 
formed in the excavations made by resorption has been termed by Henry 
inostosis. The new-formed tissue in inostosis is sometimes of very peculiar 
character. Occasionally it resembles osteodentin, at other times it has the 
appearance of enamel. Fig. 609 is a case from the private collection of the 
writer which shows a pearl-like body in the side of the root of a third 
lower molar, occupying a cavity apparently formed by resorption. Fig. 
610 is a microscopic section of a similar case from the private collection 
of Dr. V. A. Latham, but lying deeper in the dentin. 

These phenomena represent two distinct vital processes, processes 
which are antagonistic to each other. One is formative, the other de- 



516 OPERATIVE DENTISTRY. 

structive. The explanation would seem to lie in the character and degree 
of the irritation, operating at different periods or in different locations at 
the same period. 

It has already been noticed that a mild and continuous chronic irri- 
tation of the peridental membrane favors the production of new cement- 
tissue through stimulation of the cementoblasts, while it is a recognized 
fact that another form of irritation, which is perhaps only a little more 
severe, will establish a retrograde or destructive process in the tissues, as 
noted in the resorption of bone by the stimulation of the osteoclasts. A 
similar condition doubtless takes place in the resorption of the cementum, 
for there are often found attached to such teeth masses of tissue composed 
of giant-cells which cannot be distinguished from the multinucleated cells 
found in the " absorbent organ" attached to exuviating deciduous teeth. 
It has never been definitely determined whether there are two distinct sets 
of cells — cementoblasts and cementoclasts — or whether the cementoblasts 
under different stimuli do not perform both functions of formation and 
of resorption. 

Specimens are occasionally exhibited in which well-marked resorption 
was present upon one side and hypercementosis upon the other, which 
would indicate that these processes were the result of localized irritations 
of different degrees. 

Although this excessive growth of the cementum may result in the 
fusion of the roots of a tooth, or of the roots of contiguous teeth, or of the 
crown of one tooth with the roots of another, as shown in Dr. Wright's 
specimen (Fig. 602), no authentic evidence, to the knowledge of the writer, 
has so far been presented of fusion of the cementum with the alveolar pro- 
cess. Bones often become anchylosed by fusion of their surfaces, the result 
of the healing process, as, for instance, in the temporo-maxillary articula- 
tion following traumatisms or inflammation of the joint. Sometimes the 
new-formed tissue in hypercementosis seems to establish a union with the 
alveolus, and when the tooth is extracted it not infrequently causes one of 
the plates of the alveolar process to be fractured and brought away adherent 
to the root ; but upon a closer examination it is found that the bone can be 
detached from the hypertrophied cement tissue after more or less effort, as 
the tissues remain separated by a modified pericemental membrane, the 
iibres of which seem to be very strong and firmly attached to both tissues. 

Symptoms and Diagnosis.— The local symptoms of hypercementosis 
are usually negative, and unless the affection causes pain in the tooth or its 
surroundings its presence may never be suspected. 

Occasionally, however, the patient may complain of symptoms which 
would indicate pericemental irritation, — viz., slight soreness and elonga- 
tion, tenderness to percussion, and pain in the region of the tooth. Some- 
times tumefaction of the alveolar process over the root may be observable 
and this may be slightly tender to pressure, but, as a rule, no such positive 
diagnostic signs are presented. 

When pain is present, it is usually of the reflex, neuralgic order, and 
generally referred to some remote portion of the face or head or to the 
eyes or the ears. Numerous cases have been placed on record from time to 



HYPEKCEMENTOSIS. 517 

time, in the periodical dental and medical literature, of persistent neural- 
gias in these locations and of functional disorders of the eyes and ears, 
which have been traced to the presence of hypercementosis of the teeth, 
and the diagnosis has been proved by the cure of these affections following 
the extraction of the teeth. 

Serious derangement of the general nervous system may also result from 
this form of irritation. Tomes* mentions " two cases in which epilepsy 
appeared to be dependent upon diseased teeth, the most prominent feature 
being hypercementosis of the roots." 

Chorea has also been traced to the irritation of diseased teeth, particu- 
larly to pulp irritation and hypercementosis. These nervous diseases are 
common in institutions for feeble-minded children, and it was the experi- 
ence of the writer when serving upon the staff of one of these institutions 
that many times dental irritation was the cause of these affections, as 
was proved by the abatement of the symptoms after the extraction of the 
offending teeth. 

The diagnosis of hypercernentosis is often a problem which presents the 
greatest difficulties, and in many cases it can only be reached by a process 
of exclusion. Pain or other symptoms of uneasiness which are not refer- 
able to any other cause may be the only symptoms present. The patient 
sometimes says the tooth feels enlarged or swollen and sensitive to percus- 
sion, but these again may be the only symptoms to guide in the diagnosis. 

Many persons are subjects of hypercementosis, sometimes to a consid- 
erable extent, without ever having suffered the least inconvenience there- 
from, this condition of the teeth not being recognized until, for some other 
reason, the teeth have been extracted. 

The best and most reliable means of diagnosing hypercementosis is by 
means of the Bontgen rays. The picture thus obtained, if made by an 
experienced operator, brings out the outlines of the teeth and the position 
and size of their roots in such a clearly defined manner that the diagnosis 
of hypercementosis, if it existed, could not help but be correctly made. 

It is not necessary for the dental surgeon to go to the expense of buying 
apparatus for this purpose, for all large cities, and nearly all first-class hos- 
pitals, have such facilities for diagnosis and expert attendants ready to 
photograph any part of the body that may be desired, and thus relieve the 
dental adviser of all anxiety as to obtaining a good picture, or of the fear 
of accidents which sometimes come as a result of oft-repeated or long 
exposure to the effects of the Crookes tube. 

Treatment. — The only treatment to be recommended for hypercemen- 
tosis is the immediate extraction of the diseased tooth as soon as the diag- 
nosis is assured. Immediate relief is not always obtained, but usually, 
even in the severest forms of He douloureux dependent upon this cause, the 
pain will abate after a few days. Functional affections of the eyes and ears 
which have hypercementosis as their cause, rapidly improve after the 
extraction of the tooth. In the general nervous affections dependent upon 
the same cause equally favorable results follow. 

* Dental Surgery, 4th edition, p. 471. 



CHAPTEE XXXVI. 

NECROSIS OF THE TEETH. 

Definition. — The term necrosis (Greek, vexpos, dead) is generally used 
in its broadest sense to indicate death in any form, whether death of indi- 
vidual cells, aggregations of cells, or masses of complex tissues. 

In its more restricted sense it is used to indicate death of tissue en masse, 
while the term necrobiosis is used to indicate death of cells. In surgery 
the term necrosis is still farther restricted, and is generally applied to 
death en masse of bone and like hard structures, while the term gangrene 
is applied to death en masse of soft tissues. 

The term necrosis would therefore, when applied to the teeth, indicate 
death en masse of these organs. 

The teeth receive their blood-supply and nutrition from two sources, — 
viz., from the pulp and from the peridental membrane. The character of 
the teeth is such that the vitality of the pulp of a diseased tooth may be 
destroyed and the tooth still retained in the jaw for an indefinite period, 
through its organic connection with the alveolus, by means of the cemen- 
tum and the pericementum. If, however, the vitality of the pericemen- 
tum is destroyed, the tooth has no further vital connection with the alveo- 
lus, for under such circumstances the same cause which destroyed the peri- 
cementum will also destroy the pulp, when the tooth may be termed 
necrosed, and it is exfoliated as a foreign body. Nature is always intol- 
erant of any useless or dead member and immediately sets in operation 
certain forces to rid itself of the incubus. The expulsion or exfoliation 
of a necrosed tooth is attended with more or less local inflammation and 
suppuration of the surrounding parts, the integrity of which will depend 
upon the cause of the necrosis and the condition of the surrounding tissues. 

When death of the pulp occurs a partial necrosis of the dentin follows, 
but this from the clinic stand-point does not mean the loss of the tooth, for 
such teeth, if properly treated by extirpating the devitalized pulp and fill- 
ing the canals, may remain without untoward symptoms as useful members 
of the dental arch for many years, though they are not as valuable nor 
generally so long preserved as teeth with vital pulps. The probabilities 
are that the dentin may still receive under such circumstances a certain 
amount of nutrition through the cementum and the granular layer of Pur- 
kinje. This, however, is not endorsed by some authorities. A tooth 
which has lost the vitality of its pulp is, therefore, strictly speaking, in a 
state of partial necrosis. Some authorities have maintained that in cer- 
tain debilitated conditions of the pericementum the devitalization of the 
pulp would prove helpful in establishing more normal conditions in it 
by diverting the blood, which was originally intended to supply the pulp, 
to the vessels of the pericementum. It is somewhat doubtful whether the 
vessels of the pericementum could carry the extra supply of blood without 
518 



NECROSIS OF THE TEETH. 519 

producing an abnormal hypersernia, and thus defeat the very object that 
the operation was intended to secure. 

Necrosis of the cementum is due to the destruction of the pericementum, 
as this membrane is its principal means of nutrition during the vitality of 
the tooth and its only means after the devitalization of the pulp. Necrosis 
of the cementum may be partial or complete. Partial necrosis of the cemen- 
tum is common, but complete necrosis is rare. 

Causes. — The causes of necrosis may be divided into systemic, or 
general, and local ; predisposing and exciting. 

The general predisposing causes are all those conditions which in any 
way produce debility or disease of the pericementum, while the exciting 
systemic causes may be such diseases as syphilis, scurvy, mercurialism, 
iodism, etc. 

The predisposing local causes are malocclusions, loss of occlusion, local 
inflammatory conditions of the gums and alveolar process, and death of 
the pulp. 

The local exciting causes may be mechanic irritants, like cervical salivary 
deposits or a rubber band which has been placed upon the crown of the 
tooth and has been lost beneath the gum ; the pressure from an ill-fitting 
crown, clasp, or plate ; root fillings which have passed the apical canal 
and impinge upon the apical tissues ; chemic irritants like arsenic, chromic 
acid, and caustic potash ; septic conditions arising from a devitalized pulp 
or from unhygienic conditions of the mouth ; phagedenic and gouty peri- 
cementitis, and severe traumatisms like blows and falls or the too rapid 
movement of the teeth in regulating. 

Partial necrosis of the cementum may vary in extent from a very small 
area at the apex of a single-rooted tooth to an entire root of a double- or 
treble-rooted tooth. The cementum is rarely necrosed in teeth having 
vital pulps, as is evidenced by the fact that in the recession of the peri- 
cementum, gum, and alveolus, which sometimes occurs from diseases affect- 
ing these tissues, the cementum usually maintains its sensitiveness and 
responds vigorously to all forms of irritation whenever the influences of 
these agents are brought to bear upon it. Necrosis of the cementum, 
either in part or in whole, is therefore dependent upon death of the pulp 
and upon partial or complete destruction of the peridental membrane. 

The most common form of partial necrosis is that which occurs at the 
apex of the root following alveolar abscess. 

In these cases the apex of the root is denuded of its pericementum by 
the septic inflammation which has been present in the apical space and 
the denuded portions bathed in pus for a considerable period. This 
necrosed tissue, however, when not too extensive, may, if the septic con- 
ditions are removed, be resorbed, and later a redeposition of cement tissue 
take place as described in the chapter on " Resorption of the Teeth." 

Another but less common form of partial necrosis of the cementum is 
that in which an entire root of a multirooted tooth, most often the lingual 
root of the superior molars, may be entirely divested from the cervix to 
the apex of its pericemental membrane, alveolar process, and gum, or the 
gum and alveolar process may remain intact. 



520 OPERATIVE DENTISTRY. 

Such conditions usually occur in pulpless teeth, but occasionally the 
pulp in the exposed root only will be dead, while in the others it may 
still be vital and the tooth firmly held in place by the attachment of 
the buccal roots. If under such circumstances the tooth is opened, the 
living portions of the pulp devitalized and extirpated, and the root- canals 
filled, the lingual root may be amputated with engine burs or disks and 
the balance of the tooth allowed to remain. Teeth treated in this manner 
have been known to do good service for several years. 

Complete necrosis of the cementum may be caused by acute or chronic 
inflammatory conditions of the pericementum which may be dependent 
upon general or local conditions. 

When complete necrosis of the cementum has occurred as the result 
of an acute inflammation of the pericementum, the tooth is no longer 
tolerated by the system, but becomes as a foreign body and is speedily 
expelled. Under these circumstances the tooth is in a septic condition, 
and the inflammatory process which is established as a result of septic irri- 
tation is often very active, causing great pain, suppuration and discharge 
of pus at the cervix, considerable tenderness and swelling of the gums and 
surrounding tissues, and looseness of the tooth, which after a few days or 
weeks is either picked out with the fingers or drops out. 

When complete necrosis occurs as a result of a chronic inflammation, 
the process of expulsion is usually very slow, chronic suppuration, loose- 
ness of the tooth, and periodical soreness being the chief symptoms, and 
several months or years may be required for its complete exfoliation. 
Fig. 611 shows a superior central incisor which was completely necrosed 
and expelled as a result of chronic inflammation induced by drilling 
through the side of the root and of the protrusion through the opening 
of a gutta-percha filling. The root is slightly eroded upon the labial 
surface by the action of the odontoclasts, and a thin scale of calcic 
concretion has formed upon the lingual surface. Fig. 612 is a crowned 
superior central incisor which had lost its natural crown by a traumatism 
while the lad was playing ball. The root had been filled with cotton and 
the crown set with cement. For several years the tooth had been loose, 
and was finally extracted with the fingers. Extensive resorption had taken 
place at the apex, exposing the apical end of the cotton filling. 

Fig. 613 is a transplanted superior central incisor which had been 
crowned before transplanting. For six years the tooth did well, when 
suddenly it became very sore and loose, and was expelled after a few weeks. 
On the distal surface at the cervix is a depression caused by resorption 
which has penetrated to the pulp-canal, exposing the cement with which 
it was filled. Fig. 614, a necrosed superior cuspid, was the seat of a 
chronic abscess for many years ; the tooth finally became so loose that it 
was extracted with the fingers ; it shows extensive resorption at the apex. 

In cases of complete necrosis of the cementum the only treatment is 
extraction. 



lilling 




Cotton H 






Fig. 615.— Epithelial scales and salivary corpuscles from soirtes of the mouth. X 50. 



CHAPTEE XXXVII. 

DEPOSITS UPON THE TEETH. GEEEN STAINS. CALCIC DEPOSITS. 

Green Stains. — The simplest deposits that are found upon the teeth 
are the green stains so common at the margin of the gums upon the anterior 
teeth of children and young people and persons of adult age who pay 
little attention to the cleanliness of their mouths. 

These deposits are probably formed by the growth of the leptothrix 
buccalis and certain forms of chromogenic mouth-bacteria which have 
attached themselves to remains of Xasmyth's membrane or a roughened 
surface of the enamel. 

Their continued presence causes a softening and disintegration of the 
polished surface of the enamel, which leads to decay. It is, therefore, 
important that they should be removed early, and if the enamel has become 
eroded it should be ground smooth with fine Arkansas stones and polished 
with fine pumice and precipitated chalk. 

Calcic Deposits. — The calcic deposits which are formed upon the 
teeth are classed as salivary and serurnal, or as "ptyalogenic" and "hema- 
togenic" (Pierce). The first are formed from the calcic elements of the 
saliva, the second from the calcic elements of the blood, combined with 
certain waste or end-products formed from imperfect metabolism. 

The formation of salivary deposits is usually the result of local causes, 
but certain general conditions act as predisposing factors. The formation 
of serumnal deposits is largely the result of constitutional conditions, as, for 
instance, rheumatism and gout, febrile diseases, and certain kidney 
affections, like diabetes and albuminuria, which may produce local necro- 
biosis of the pericementum, terminating in pus formation or in caseous or 
calcic degeneration of the pus and the formation of adherent concretions. 

The saliva of the human mouth always contains calcic salts in greater 
or less quantity. These salts are, under certain conditions, deposited 
upon the teeth or in the ducts of the glands in the form of concretions or 
calculi, which are more or less hard and mixed with epithelial scales, lep- 
tothrix, and food debris. The deposit or concretion thus formed upon the 
teeth is called salivary calculus, or u tartar," and the concretions formed 
within the salivary ducts are termed salivary calculi. 

These deposits are found in greatest abundance upon the surfaces of 
those teeth which are situated opposite the ducts of the salivary glands, — 
viz., the buccal surfaces of the first and second superior molars, and the 
lingual surfaces of the inferior incisors and cuspids, and in those locations 
where the conformation of the teeth renders the deposits least liable to be 
disturbed, — viz., upon the proximate surfaces and crevices of the teeth 
beneath the free margins of the gums. 

Composition of the Saliva. — The most important constituents of 
normal mixed saliva are ptyalin, — a diastatic ferment, — mucin, and the 

521 



522 OPERATIVE DENTISTRY. 

chlorides of sodium and potassium ; in addition to these there are found 
traces of albumin, fat, potassium sulphocyanide, sulphates and phosphates of 
the alkalies and alkaline salts, principally calcic phosphate, also calcic car- 
bonate and oxide of iron. Occasionally there are found also, even in normal 
saliva, traces of urea and ammonium nitrite. 

The average daily amount of saliva excreted ranges from 800 to 1500 
grammes, or from a little less than a quart to three pints. Tomes places it 
at from 13 ounces to 31 pounds. 

According to Lehmann, the specific gravity of the saliva ranges in 
health from 1004 to 1006. He states, however, that it may rise to 1008 or 
1009 or even sink to 1002 without the evidence of any existing disease. 

According to Berzelius, normal mixed saliva gives the following 
analysis : 

Water 992.9 

Solids 7.1 

Ptyalin 2.9 

Mucin 1.4 

Sulphocyanide 1.4 

Salts 1.9 

According to Frerichs, — 

Water 994.10 

Solids 5.90 

Epithelium and mucus ... 2.13 

Fat 0.07 

Mucin and traces of alcoholic extract 1.41 

Potassium sulphocyanide 0. 10 

Chlorides of sodium and potassium, phosphates of sodium and po- 
tassium, and oxide of iron 2. 19 

According to Jacobowitsch, — 

Water 99.51 

Solids 0.49 

Soluble organic bodies, ptyalin, etc 0. 130 

Epithelium 0.160 

Inorganic salts 0. 182 

Potassium sulphocyanide 0.006 

Potassium and sodium chloride 0.084 

The saliva as found in the mouth is a mixed fluid, being composed of 
the secretions of the various salivary glands — parotid, submaxillary, and 
sublingual — and of the oral mucous glands, its chemic and physic prop- 
erties varying as the secretion from one or the other of these glands may 
predominate. In character it is generally a clear viscid or glairy fluid, 
containing epithelial cells, mucous corpuscles, and salivary corpuscles. 
The character, however, often varies considerably ; at times it may be a 
thin, watery fluid, at other times thick and ropy. 



DEPOSITS UPON THE TEETH. 523 

The chemic reaction of mixed saliva is slightly alkaline, but when the 
secretions are scanty it may give a very slightly acid reaction. Saliva 
tested in the mouth with litmus paper often gives an acid reaction ; but 
this is many times due, no doubt, to the formation of acids within the 
mouth from the fermentative action of the acid-producing bacteria upon 
alimentary debris. 

The excretion of the parotid gland contains a trifle more water and is 
less viscid than the secretions of sublingual and submaxillary glands ; it 
contains ptyalin, but no mucin ; its calcic constituents are the carbonate 
and phosphate, the calcium phosphate being in minute amount. Accord- 
ing to Hoppe-Seyler, the inorganic elements amount to 0.34 per cent. 

The secretions of the sublingual and submaxillary glands are poor in ptyalin 
but are rich in mucin ; the sublingual contains the highest per cent. Car- 
bonate and phosphate of calcium are found in about equal proportions. 
These elements amount to about 0.43 per cent, in the submaxillary se- 
cretion, but the percentage is not so high in the secretion of the sub- 
lingual. 

The secretion of the mucous glands contains a large amount of mucin. 
The organic and inorganic constituents average about 20 parts to 1000. 

The calcic substances of the saliva are held in solution by the presence 
of a sufficient quantity of carbon dioxide (CO.,). This combination, how- 
ever, is so unstable, that as soon as the saliva is exposed to the oxygen 
of the atmosphere or to the acids of fermentation produced in the mouth, 
or is at rest, the carbon dioxide escapes, and the calcic elements, being no 
longer able to maintain solubility, are precipitated and collect upon the 
teeth, thus forming what is known as salivary calculus, or tartar. 

It is necessary, however, that the enamel be roughened or uneven, or 
that leptothrix threads have found attachment to Nasmyth's membrane or 
the enamel, in order that a nidus be presented for the formation of the 
concretion. 

The viscid tenacious character of the saliva, however, is sufficient to 
form a nidus for the collection of tartar upon the teeth when for any reason 
— but particularly in the continued fevers and other wasting diseases — the 
mucin becomes dried upon the teeth, forming masses of sordes. These 
masses of dried mucin contain innumerable epithelial scales and salivary 
corpuscles. See Fig. 615. It is possible, also, that the particles of the 
calcic deposit are held together by the agglutinating effect of the coagulated 
mucin. 

Kirk, however, believes there is a more intimate relation between the 
organic substances and the calcic elements of the tartar than their mere 
cementing properties. He thinks conditions exist which are somewhat 
similar to those under which calcoglobulin is formed, and suggests that 
salivary calculi bear a family resemblance to calcoglobulin. 

Salivary calculus is composed, according to Berzelius, of : 

Phosphates of calcium and magnesium 79.0 

Salivary mucus 12.5 

Ptyalin 1.0 

Animal matter soluble in HC1 7.5 



524 OPERATIVE DENTISTRY. 

According to Charles, its average composition is as follows : 

Calcium phosphate 55 to 64 

Calcium carbonate 7 to 8 

Ferric phosphate i 1 to 3 

Residue : organic matter, salts of alkalies, silica, etc 24 to 28 

There is a wide difference in these two analyses, but this may possibly 
be explained by the difference in the location from which the specimens 
were probably taken. 

It is but natural to suppose that, inasmuch as the parotid secretion con- 
tains an abundance of calcium carbonate and only a minute amount of 
calcium phosphate, the concretions formed upon the teeth opposite Steno's 
duct would be composed largely of calcium carbonate ; while, upon the 
other hand, the concretions formed upon the lower incisors opposite the 
ducts of Wharton would be composed equally of calcium carbonate and 
calcium phosphate, as the secretions of the sublingual and submaxillary 
glands contain about equal portions of these salts. 

Magitot claimed that the salivary calculus formed in the region of the 
parotid glands was almost wholly carbonate, while that formed upon the 
inferior central incisors was largely phosphate. 

Alfred Vergne claimed that the calculus formed upon the superior 
molar teeth had less phosphate than that upon the inferior incisors, but 
that the carbonate was about equally distributed. 

Salivary calculi, or the concretions found in the ducts of the salivary 
glands, are usually composed largely of calcium phosphate. They -are 
generally of an elongated form, dirty yellow to brown in color, and are 
formed in concentric layers. They contain no leptothrix, and vary in 
size, form, appearance, and composition. 

The following table, prepared by Charles, gives the average compo- 
sition : 

Calcium phosphate 30 to 80 per cent. 

Calcium carbonate 11 to 15 " " 

Organic matter 5 to 12 " " 

Magnesium oxide, iron oxide, sodium chloride, sulphates, and potas- 
sium sulphocyanide have all been found as components of salivary calculi. 

Calculi composed largely of uric acid have been found in the salivary 
ducts of individuals suffering from the uric-acid diathesis. 

Varieties. — It has been customary among the earlier writers to classify 
the varieties of salivary calculus, or tartar, according to its color and 
density, as though the difference in these respects was a sufficient ground 
for designating it as a separate variety. 

Salivary calculus varies in color from light yellow to black, and be- 
tween these extremes it may present any shade of green or brown. In 
physical characteristics it may be soft or hard, brittle or coherent, but 
neither of these features or characteristics is of sufficient importance, 
either from a pathologic or a clinic stand-point, to form the foundation of 
a classification. All of the differences in color may be readily accounted 



DEPOSITS UPON THE TEETH. 525 

i 

for by the fact that the micro-organisms of the mouth are capable, through 
their chrornogenic function , of imparting to the deposits any shade of 
these colors ; while, upon the other hand, the ingestion of certain kinds of 
food and of medicines and the use of tobacco, either chewing or smoking, 
will also produce a change in the color of the concretions. Smoking pro- 
duces a black color of the tartar, but time and the action of the micro- 
organisms will, as in caries, produce similar dark colors. 

The physical characteristics are likewise governed by the element of 
time. Tartar that is freshly deposited is soft and yellowish-white in color, 
and so chalky in its nature that the slightest effort is sufficient to dislodge 
it in bulk ; while that which has been deposited for a much longer time 
will be hard and brown or black in color, and require considerable force 
to dislodge it. The older the deposit becomes the darker will be its color. 
Its density, brittleness, and coherent qualities are also dependent upon the 
element of time for these characteristics. 

Salivary calculus is formed most rapidly in a saliva which gives an 
alkaline reaction ; while if the secretions are acid, salivary calculus not 
only does not form, but if the reaction is decidedly acid, the tartar already 
formed upon the teeth may be dissolved and removed. 

Clinically there are three forms of salivary calculus : 

1. That which is formed upon the surfaces of the crowns of the teeth, 
— snpergingiva I deposits . 

2. That which is formed in isolated islands, or as a narrow band at the 
cervices of the teeth, beneath the margin of the gums, — cervical deposits. 

3. That which is formed in thin scales upon the sides of the root in 
open pockets more or less remote from the margins of the gums, — subgin- 
gival deposits. 

The first variety, or super gingival deposits, of salivary calculus is found 
upon the crowns of the teeth. It may be soft and friable or hard and 
brittle, according to the length of time which has been consumed in form- 
ing the deposit. Its color is usually a dirty white or yellow, but it may 
be any shade of green, brown, or black, according to the length of time it 
has been forming, the especial chromogenic bacteria present in the mouth, 
and the habits of the individual. This variety of tartar is clinically the 
most common, as well as the least harmful. It frequently accumulates in 
great quantities, particularly upon those teeth which are directly opposite 
the salivary ducts. Sometimes the crowns of these teeth become com- 
pletely covered with the deposits, so that the semblance of the tooth is lost. 
Figs. 616, 617, 618, and 619 show examples of such cases. 

Teeth which stand out of the normal line, particularly when located 
inside of the arch and in the lower jaw, are most often covered with such 
deposits ; such teeth may become so encrusted with the calcic material as 
to give them the appearance of necrosed and denuded bone. Such errors 
in diagnosis have been made, and serious surgical oj>erations undertaken 
for the relief of a bone disease, which might have been prevented by count- 
ing the teeth upon that side of the jaw and searching for the missing ones 
which could not be accounted for by extraction or otherwise. 

The writer well remembers such a case, in which he was acting as pon- 



526 OPERATIVE DENTISTRY. 

sultant. The tumor was situated upon the leftside of the lower jaw, upon 
the floor of the mouth, in the region of the second bicuspid, which upon 
examination was found missing. All of the other teeth were in normal 
position. The tumor was about the size of a pecan-nut and had the ap- 
pearance of necrosed bone, but the sensation conveyed by scratching it with a 
steel instrument was so different from that of dead bone that the writer was 
led to believe from this fact, and also from its location, which was directly 
beneath where the missing bicuspid should be, that the tumor was nothing 
more than the missing tooth, the crown of which was encased in salivary 
calculus. The diagnosis was proved by splitting the calculus with a chisel 
and mallet, when the halves fell apart, exposing the crown of the missing 
bicuspid tooth. 

The rapid formation of salivary calculus is indicative of a disturbance 
in the equilibrium of the metabolic process of tissue waste and repair, or, 
in other words, constructive or synthetic metabolism is not keeping pace 
with that of the destructive process. The breath and the saliva under such 
circumstances have a foul and disgusting odor. The odor left upon the 
fingers of the operator when they have been in contact with such an offen- 
sive saliva is very disagreeable, indeed, and often requires repeated bathing 
in antiseptic and deodorant solutions before it is entirely removed. 

The greatest care should be exercised in sterilizing the hands and the 
instruments used in the treatment of such cases, as the saliva is loaded 
with myriads of micro-organisms, often of the most virulent varieties. 

Salivary calculus of the first variety often presents a distinct lamina- 
tion which conforms to the outline of the surface upon which it was 
deposited. 

The pathologic effect of salivary calculus deposited upon the crowns 
of the teeth will depend upon the amount and the locality of the deposit. 
When occurring in small quantity it seems to be entirely harmless, — -in fact, 
it seems sometimes, when deposited upon a tooth with a carious defect, that 
it retards or entirely arrests the progress of the caries ; many cases have 
been seen in which the carious cavity has been filled with salivary calcu- 
lus and the disease completely arrested. It must be remembered, how- 
ever, that the conditions which favor the formation of salivary calculus do 
not favor the progress of dental caries. An alkaline condition of the 
saliva promotes the deposition of calcic material and retards dental caries, 
while an acid condition of the salivary secretions favors the progress of 
caries and retards or altogether prevents the accumulation of salivary 
calculus. 

When tartar of the first variety, or supergingival deposit, accumulates in 
large masses and impinges upon the gums, it acts as a mechanic irritant, 
and produces ulceration of this tissue, resorption of the alveolar plate, and 
recession of the gums. The accumulations may be so extensive in certain 
localities as entirely to cover the teeth and to unite them into a solid mass. 
Such accumulations have been known to involve the six anterior inferior 
teeth to such au extent as completely to destroy their attachment to the 
jaw and cause them to be exfoliated like a mass of necrosed bone. 

The second variety, or cervical deposit of salivary calculus, is found 





Fig. 616.— Salivary calculus. 



Fig. 617.— Salivary calculus. 





Fig. 618.— Salivary calculi: 



Fig. 619. — Salivary calculus. 




Fig. C'20. — Glands of Scrrcs. X 50. 



DEPOSITS UPON THE TEETH. 527 

upon the cervices of the teeth in the form of isolated islands, usually upon 
the lingual surface or in the form of a narrow band directly beneath the 
free margins of the gums. It is generally dark green or brown in color, 
very hard, brittle, and tenacious, requiring in some instances considerable 
force to dislodge it. This variety of calculus is most often found in the 
mouths of robust individuals, in those who live high, and those with 
rheumatic and gouty tendencies. 

The pathologic effect of this variety of calculus is to establish a low 
grade of chronic inflammation of the gums, ulceration of the gingival mar- 
gins, resorption or necrosis of the margins of the alveoli, and recession of 
the gums. These conditions are the result of the mechanic irritation pro- 
duced by the impingement of the calculus upon the margins of the gums 
and the pericementum. 

Acute inflammatory symptoms are rarely presented in this form of 
salivary calculus unless some traumatic injury has occurred to severely 
lacerate the gums, as by an unusual, vigorous use of the toothbrush or 
masticating hard substances. Such an inflammation may sometimes be- 
come degenerative and involve the gums of both jaws and extend to the 
hard palate, producing an obstinate ulcerative stomatitis. 

The presence of these concretions rarely produces a diffuse inflamma- 
tion of the pericementum. The inflammation is usually confined to that 
location which is the direct seat of the irritation, — viz., the margins of the 
gum and the pericementum. These tissues are gradually destroyed by the 
encroachment of the deposit and the consequent inflammation and ulcera- 
tion produced by their presence. 

This variety of salivary deposit seems to accumulate most rapidly after 
a chronic inflammatory process has been established in the free margins of 
the gums. This led Serres and some other pathologists to the supposition 
that the glandular structures of the gums (glands of Serres, Fig. 620) 
were instrumental in causing the formation of the deposits. This ques- 
tion has, however, not been satisfactorily settled. The general opinion 
seems to be, however, that the deposits come directly from the salivary 
secretions, and that the inflammatory conditions of the gingivae resulting 
from the mechanic irritation present in some way — perhaps through cer- 
tain products of the decomposition of tissue, NH 3 and H 2 S — more favorable 
conditions for the deposition of the calcic material found in the saliva than 
would be the case under other circumstances, hence its more rapid accu- 
mulation. 

The third variety, or subgingival deposit, is that which is found in thin 
scales upon the sides of the roots of the teeth in open pockets more or less 
remote from the free margins of the gums. This form of deposit and its 
effect upon the pericementum and the surrounding tissues will be dis- 
cussed in the chapter on pyorrhoea alveolaris. 

Treatment. — The treatment of the supergingival deposits, or ordinary 
form of salivary calculus, and of the cervical variety consists in removing 
the concretions from the surfaces of the teeth by the aid of various instru- 
ments known as scalers. These instruments are made with suitable curves 
and angles adapted to reach every portion of the various surfaces of the 



528 



OPERATIVE DENTISTRY. 



tooth-crown, while the blades are of such form and temper that the edges 
can be kept sharp. Fig. 621 illustrates a few of the most useful shapes 
employed for this operation. Some of these instruments are intended to 



Fig. 621. 



.^fX 



^T^\ 




Small scalers. 



be used as chisels, others as hoes or scrapers. The operation consists of 
first scaling or scraping away the accumulated mass of tartar, and after- 
wards thoroughly polishing the exposed surfaces of the teeth with pulver- 
ized pumice. This part of the operation may be done with any orange- 



Fig. 622. 






wood wedge-stick flattened at one end or by variously shaped rubber disks, 
wheels, and cups, or with small brushes, as shown in Figs. 622 and 623, 
used in the dental engine. 

Fig. 623. 





After the concretions have all been removed, the mouth should be 
thoroughly irrigated with a soothing antiseptic mouth- wash, like listerine, 
pasteurine, borolyptol, etc., followed by the spray from an atomizer 



DEPOSITS UPON THE TEETH. 529 

charged with the same solution, which should be directed into the inter- 
dental spaces to make sure that all loose particles of tartar are removed 
from between the teeth and from beneath the margins of the gums. 
Finally, to relieve any inflammation that may be present and to promote 
the healing of the gums, they may be painted with a combination of the 
tinctures of iodine and aconite in equal parts. 

The prevention of the further accumulation of salivary calculus will 
depend largely upon the time which the individual is willing to give to the 
cleansing of the teeth. Thorough brushing of the teeth after each meal 
with a suitable dentifrice and the judicious use of floss-silk and tooth-picks 
will usually prevent the further accumulation of deposits upon all accessi- 
ble surfaces. The prevention, therefore, of the accumulation of salivary 
deposits sums itself up into the question of cleanliness. Many refined 
people who are extremely neat in every other respect often present mouths 
which are positively disgusting to behold, but whose sense of refinement 
would be greatly shocked if they were told that their mouths and teeth 
were in a very filthy condition, and that they carried about in their oral 
cavities conditions which were more fatal to good health than the presence 
of sewer gas in their dwellings. 



34 



CHAPTEB XXXVIII. 

PYORRHOEA ALVEOLARIS. 

Definition. — Pyorrhoea (Greek nbbv, pus; p<na, a flow). A purulent 
discharge. Alveolaris (Latin, a small hollow). Pertaining to the alveoli, 
or the sockets of the teeth. The term, therefore, means a flow of pus from 
the alveolus of a tooth. But as this is a symptom of several other diseases 
which involve the same tissues, — viz., alveolar abscess, traumatic perice- 
mentitis, scorbutic pericementitis, mercurial pericementitis, etc., — the term 
does not seem to be well selected to express the characteristic pathologic 
features of the disease. The term pyorrhoea alveolaris has, however, been 
quite generally adopted by the profession, and for that reason it is perhaps 
better to retain it, although several others have been suggested which are 
more appropriate, as they convey a better idea of the true nature of the 
disease. 

Synonymes. — Biggs' s disease, suppuration conjointe, pyorrhoea inter- 
alveolar- dentaire, gingivitis expulsiva, osteo-periostiti-alveolo-dentaire, 
pyorrhoea alveolo, caries alveolaire specifica, cemento periostitis, infectoso- 
alveolitis, periostitis dentalis, periostitis-alveolo-dentalis, calcic pericemen- 
titis, phagedenic pericementitis, gouty pericementitis, ptyalogenic calcic 
pericementitis, hsematogenic calcic pericementitis, blennorrhoea alveolaris, 
interstitial gingivitis. 

The various terms or synonymes which have been applied to this affec- 
tion express in a certain sense the views held by the writers who have sug- 
gested them, as to the nature of the disease. 

Pyorrhoea alveolaris is a disease which primarily affects the pericementum, 
manifesting itself in a suppurative inflammation, sometimes acute in form, 
but generally of a chronic type ; and, secondarily, the inflammatory process 
involves the walls of the alveolus and the gum. This process is accompanied 
by loosening and turning or extrusion of the teeth, a discharge of pus from 
the alveolus, gradual disintegration of the alveolar process (caries), reces- 
sion of the gums, and finally the tooth loses its alveolar and gingival 
connection and falls out. 

Upon the loss of the tooth the inflammatory symptoms immediately 
subside, which proves conclusively that the local manifestations of the 
disease are primarily associated with the dental tissues, and not with the 
gingivae or the alveolar processes. 

Witzel and others have maintained, however, that the disease was 
primarily located in the alveolar border, and that the gum and pericemen- 
tum were involved as a secondary feature of the disease. 

Pyorrhoea alveolaris, next to the subject of dental caries, has attracted 

more attention from dental surgeons than any other affection of the human 

mouth. It has been thought to be a disease of modern origin and a result 

of the sins of our modern civilization ; but a visit to the ethnologic depart- 

530 



PYORRHOEA ALVEOLARIS. 531 

ments of our large museums will convince any one that the disease is not 
confined to modern times nor to higher civilization, but that in all prob- 
ability it is as old as the human race. Evidences of the disease are to be 
seen alike in ancient and modern skulls, in the skulls of aboriginal tribes, 
and also in those of barbarous, semi-civilized, and civilized nations. On 
the other hand, however, there seems to be some reason for believing the 
disease to be on the increase among civilized nations of the present day. 
Whether this is a fact or not remains yet to be proven. Statistics are 
necessary to establish such a fact, and these have not been gathered. This 
statement, however, seems quite true, — viz., the dental surgeon is called 
upon to treat more and more of these cases every year. Perhaps this is 
due to his better general knowledge of the disease, and to his ability to 
recognize its clinic aspects and manifestations not only in the fully 
developed disease but in its incipient stages ; or it may be possible that 
the disease is sometimes confounded with other affections which present 
somewhat similar symptoms and pathologic features. It is no uncommon 
thing for a chronic alveolar abscess which is discharging through the 
alveolus to be mistaken in a hasty examination for a case of pyorrhoea 
alveolaris, and vice versa. It therefore becomes exceedingly important that 
every examination should be made with the utmost care and precision, 
that errors in diagnosis may be avoided. 

Causes. — A wide difference of opinion exists among pathologists and 
dental practitioners in reference to the etiology of this disease. So much 
interest has been taken in the study of this subject in recent years that 
the literature upon the etiology of the disease has become quite voluminous, 
and nearly as confusing. The writer has found, however, that after a 
careful review of the literature these opinions can all be grouped under 
three heads : 

1. That the disease originates in some constitutional state or dyscrasia. 

2. That the disease is caused entirely by local irritation and environment. 

3. That the disease is due to the infection of the tissues with micro-organ- 
isms. 

Constitutional Origin of the Disease. — Fanchard (1746)* was the 
first to call attention to the disease and record its essential clinical features, 
but offered no opinion as to the origin of the disease, neither did he desig- 
nate it by any specific term. 

Jourdain (1778) f published a communication describing the disease, 
and made the suggestion that it was of scorbutic origin, and termed it in 
its later stages u conjoined suppuration," because it is then complicated with 
a purulent discharge from between the margins of the gums and the 
cervices of the teeth and a gradual destruction of the alveolar processes. 

Toirac (1822), J in his communication upon the disease, termed it 
" pyorrhoea-inter- alveolo-dentaire, 7 ' but failed to offer an opinion upon the 
origin of the disease. 

* Independent Dental Journal, 1875. 

f Philadelphia Journal of Medical and Physical Sciences, 1821. 

X Journal of the American Medical Association, 1879. 



532 OPERATIVE DENTISTRY. 

Bell (1829)* described the disease in all of its clinical features, and 
divided the affection into two distinct forms, one dependent upon the 
formation of deposits upon the teeth, the other caused by a constitutional 
condition which may be looked upon as a sort of premature old age. He 
says, "In forming a judgment upon cases of this description, however, 
and even upon those in which the loss of substance is associated with more 
or less of diseased action, it is necessary to recollect that the teeth are 
generally removed in old age by this identical mode, — namely, the de- 
struction of their support by the absorption of the gums and the alveolar 
processes ; and as this step towards general decay commences at very 
different periods in different constitutions, it may doubtless in many cases, 
even in persons not past the middle period of life, be considered as an in- 
dication of a sort of premature old age, or an anticipation, at least, of 
senile decay, as far as regards these parts of the body." 

Harris (1853) f termed the disease a u chronic inflammation of the gums," 
dependent upon morbid constitutional conditions as predisposing causes, 
such as "bilious and inflammatory fevers, the excessive use of mercurial 
medicines, the venereal virus, intemperance, and debauchery ; while any 
deterioration of the fluids of the body is peculiarly conducive to it. Per- 
sons of cachectic habit are far more subject to it, and generally in the worst 
forms, than those individuals in the enjoyment of good health." As im- 
mediate or exciting causes he mentions the i i local irritation of salivary 
calculus, carious, dead, loose, or aching teeth or roots of teeth, or teeth 
which occupy a wrong position or that are crowded in their arrangement." 

Marechal de Calvi (1860) J looked upon the disease as an hereditary 
constitutional disorder, and termed it gingivitis expulsiva. 

Magitot (1867), § in his admirable paper upon the nature of the dis- 
ease, describes it as a slow but progressive inflammation causing the 
destruction of the periosteal membrane and the cementum, which begins 
at the cervix and extends to the apex of the root, and involves the loss 
of the tooth. The term by which he designated the disease was ' ' osteo- 
periostiti-alveolo-dentaire," as this was the exact seat of the disease. He 
believed the disease was primarily located in the pericementum, and that 
soon after the appearance of the inflammation in the membrane the gums 
and osseous walls of the alveolus became involved, but that the disease 
was never primarily located in those latter tissues. 

He viewed the causes of this peculiar inflammation as very complex. 
In his opinion the origin of the disease lay in a faulty general nutrition. 
Persons of a gouty and rheumatic diathesis furnished the greatest number 
of cases, but it was also very common in individuals suffering from dia- 
betes mellitus, albuminuria, and anaemia. 

The formation of calcic deposits upon the teeth he regarded as purely 
accidental and playing no important part in the etiology of the disease. He 



* Anatomy, Physiology, and Diseases of the Teeth. 
| Dental Surgery. 

J Journal of the American Medical Association, 1897. 
\ Etudes et Experiences sur la Salive, Paris. 



PYORRHOEA ALVEOLARIS. 533 

advised, however, as an indispensable preliminary to any form of treat- 
ment, the thorough removal of all concretions upon the roots of the teeth. 

Wedl (1870),* in describing the disease, says, "That portion of the 
root-membrane which is in relation with the submucous connective tissue 
of the gums appears to be attacked secondarily in most cases, in conse- 
quence of the extension of the disease, either from the enclosed extremity 
of the root-membrane or from the inflamed gums. In these cases the gum 
becomes detached from the neck of the tooth, and pressure upon the 
alveolus forces out a puriform fluid. This condition results, without 
notable pain, in the loss of the affected tooth." In reference to the 
causation of the disease he says, "In these cases, then, we have to do, 
first of all, with a catarrhal inflammation of the gum, which afterwards 
extends to the root-membrane." 

Brown (1870) f was the first to suggest that the disorder was due to the 
formation of certain deposits upon the roots of the teeth, which were 
derived from the serum of the blood, and which he denominated serumal 
calculus. 

Salter (1875) J denominates the disease "false scurvy," and believes it is 
more or less the manifestation of constitutional vice, being frequently 
associated with chronic dyspepsia and general ill-health, and as a result in 
females of frequent pregnancies. Certain drugs, like mercury and iodide 
of potassium, when given to excess have the power of producing the 
disease. 

Sirlette (1876), § in discussing the etiology and pathology of this dis- 
order, stated that he regarded the disease as due to certain constitutional 
conditions, such as rheumatism, scrofula, syphilis, diabetes mellitns, albu- 
minuria, etc., but that certain local conditions acted as exciting factors. 
He denominated the affection "periostitis-alveolo-dentalis." 

Taft (1876)|| regarded pyorrhoea alveolaris as arising from a general 
disorder of health, and unless the general state of the health was improved, 
local treatment would be of no avail. 

Rehwinkle (1877),^[ in a paper upon the "Causes and Treatment of 
Pyorrhoea Alveolaris," says the origin of the disease can often be traced to 
the action of mercury, and in other cases to constitutional and inherited 
predisposition, while it often exists independently of foreign deposits and 
in the cleanest of mouths. 

Davis (1879),** in a paper on " Gum and Alveolar Diseases," says he is 
unable to account for the phenomena of Eiggs's disease, except upon the 
hypothesis of atrophy of the peridental membrane or of the external fibrous 
covering of the alveolus, while the deposits which are found upon the 
roots of the teeth are an accidental sequence, and not a cause of the disease. 

* Pathology of the Teeth, 
t American Journal of Dental Science. 
| Dental Pathology and Surgery. 
§ Gazzetta Medica di Roma, 1876. 
|| Operative Dentistry. 
\ Dental Cosmos vol. xix. 
** Ibid. 



534 OPERATIVE DENTISTRY. 

Cowles (1879),* in a discussion upon the subject of " Biggs' s Disease," 
said, "Wedging is a great producer of this difficulty, and therefore I am 
opposed to wedging, but a more general cause than all others is the lack 
of nutrition in the parts." 

Essig (1879) f expressed the opinion that the primary cause was prob- 
ably systemic ; that it usually makes its appearance in mouths which were 
remarkable for an almost complete immunity from dental caries ; and this 
fact has led to the assumption that such evident power of resisting the 
usual causes of decay until middle life implies extreme density and low 
degree of vitality in the structure of the teeth, resulting in a final sever- 
ance between them and the more highly vitalized contiguous parts, thus 
constituting a predisposing cause of a disease liable to be developed by an 
accretion of calculus or other excitant. The disorder, he thinks, is a local 
manifestation of a constitutional cause, and the calcareous deposit merely 
an accident of opportunity. 

Serran (1880) J believed that the primary manifestation was a local con- 
gestion of the gums, followed by an inflammatory exudation in the peri- 
dental membrane, loss of vitality in the structure, the formation of pus, 
and all of the other symptoms and pathologic features which are charac- 
teristic of the disorder. He recognized the fact, however, that the disease 
was most common in the middle period of life, and that individuals suffer- 
ing from gout, rheumatism, diabetes mellitus, and albuminuria furnished 
the principal number of cases. These statements were in certain respects 
in opposition to the views expressed by Magitot in 1867 relative to the 
tissues which were primarily involved in the disease. 

A commission appointed by the Societe de Chirurgie to consider the 
statements of Serran denied the gingival origin of the disease, and sub- 
stantially upheld the views of Magitot. 

Mills (1880) § claimed that the cause was systemic, and the deposit only 
a local manifestation. He believed, also, that age was not the only factor 
in the production of the disease, but that various influences, physical and 
mental, were often powerful abettors of the disease. Conditions of ner- 
vous exhaustion may exist at certain periods of life, permitting the local 
expression of a disease which altered circumstances in after-life may radi- 
cally modify. In his opinion the disease not infrequently appeared in the 
mouths of youths, generally as a sequence of one of the eruptive fevers. 

Atkinson (1881) || was of the opinion that the disease was of consti- 
tutional origin, the result of nervous debility or original defective innerva- 
tion, and the deposit a sequence of the disorder, but never the cause. 

Coles (1881) ^[ was of the opinion that certain systemic conditions acted 
as predisposing causes, and micro-organisms as local exciting causes. 

Ingersoll (1881),** in a paper upon "Sanguinary Calculus," maintained 

* Dental Cosmos, vol. xxi. 
t Ibid., vols, xxii., xxiii. 

J Bulletins et Memoires de la Societe de Chirurgie, tome vi. p. 411. 
§ Dental Cosmos, vol. xxiii. || Ibid. 

lj International Medical Congress, 1881. 
** Ohio Dental Journal, 1881. 



PYORRHCEA ALVEOLARIS. 535 

that certain concretions were formed upon the roots of teeth which could 
not be derived from the saliva, as they were formed near the apex of the 
root, and under circumstances which made it impossible that they could 
be of salivary origin. This form of calculus contained a dark coloring 
matter, and was always found in connection with ulceration and a discharge 
of pus. The liquor sanguinis contained the lime-salts in solution, and these 
were crystallized and deposited upon the roots of the teeth. 

As this form of concretion could not have come from the saliva, he con- 
cluded that it must have come from the blood, and he therefore termed it 
sanguinary calculus. 

This opinion is very similar to that expressed by Brown in 1870, which 
has already been quoted. 

Bawls (1885)* believed the causes were primarily of systemic origin, 
as expressed in inherited and acquired tendencies, habits, and environ- 
ment. Malarial fever, mercurial ptyalism, etc. , and the excessive use of 
sodium chloride were all important factors in the production of the disease. 

Reese (1886) f was of the opinion that the disease was due to the pres- 
ence of the uric acid diathesis resulting from the abuse of alcoholic stimu- 
lants. 

Patterson (1886) J revived the theory of Wedl that the disease was due 
to a catarrhal condition of the oral mucous membrane and the gingivae 
(oral catarrh). Patterson also believed that pyorrhoea alveolaris, like 
catarrh, was contagious, and sometimes even epidemic. 

Farrar (1886) § looked upon the disease as being the result of a combi- 
nation of systemic conditions and tendencies and local irritants, and held 
that there was a peculiar systemic condition associated with hypersecretion 
and an increased amount of earthy deposits. 

Starr (1886) 1 1 regarded the disease as due to certain systemic conditions 
and tendencies, and associated with some undetermined local irritating 
factor. He was of the opinion that this local factor was the same as that 
which caused hypercementosis. He also stated that in his experience a 
majority of the teeth affected with pyorrhoea alveolaris were found in the 
upper jaw. 

Sudduth (1887) ^| expressed the opinion that pyorrhoea alveolaris was a 
sequel, or rather the secondary stage, of a disease which had its inception 
in a catarrhal stomatitis. In fact, he thinks he is justified in classing the 
disease as a localized catarrhal stomatitis which is dependent upon hered- 
itary dyscrasia for its constitutional factor. The disease may be either 
acute or chronic. 

Sutton (1887) ** regards the disease as undoubtedly of constitutional 
origin, as expressed in gout, rheumatism, mollities ossium, and other 
wasting diseases. 

* Dental Cosmos, vol. xxvii. 

t Transactions of the Louisiana State Dental Society, 1886. 
% Dental Cosmos, vol. xxvii. 

§ Independent Practitioner, vol. vii. || Ibid. 

If Sajous's Annual, 1888, vol. iii. 
** Dental Record, 1887. 



536 OPERATIVE DENTISTRY. 

Marshall (1891) * expressed the opinion that in many cases the origin 
of the disease could be traced to the rheumatic and gouty diathesis, and 
that the deposition of the concretions upon the roots of the teeth in those 
localities not easily reached by the saliva, or in which the presence of the 
saliva would be an impossibility, is due to the same cause which produces 
the chalky formations found in the joints and fibrous tissue of gouty and 
rheumatic individuals, and suggested that these deposits were formed of 
urates of lime and soda. 

Pierce (1892, 1894, and 1895) f in a series of papers presented a num- 
ber of clinic and pathologic facts which in their totality seemed to estab- 
lish the kinship between pyorrhoea alveolaris, or hematogenic calcic peri- 
cementitis, and the systemic condition generally recognized as the gouty or 
uric acid diathesis. 

Darby (1894) J strongly upheld the theory of the constitutional origin 
of the disorder, and ascribed it to the uric acid diathesis. 

Burchard (1895) § believed the disease to be due to constitutional and 
local predisposing causes and to local exciting causes. Among the consti- 
tutional predisposing causes he mentions hereditary influences, particu- 
larly arthritic diseases and the diseases of suboxidation and faulty elimina- 
tion ; among the local predisposing causes are overuse, disuse, and misuse 
of the teeth. These also often act as direct exciting causes. Subgingival 
deposits also act as exciting causes. 

C. H. Tomes (1897) 1 1 regards the causes and pathology of the disease 
as very obscure. There is much to support the idea that a constitutional 
cause is at the bottom of it, — for instance, it usually occurs with some near 
approach to bilateral symmetry, and the teeth first affected are often not 
those most liable to the deposit of tartar, — while he assigns to tartar a 
merely secondary influence in the progress of the disease which comes into 
operation only after the mischief has begun. 

He does not, however, subscribe to the uric acid theory. 

Harlan (1898) ^[ regarded the disease as being largely influenced by 
heredity and acquired conditions, deposits acting as exciting causes. 

Ehein (1899) ** divides the disease into pyorrhoea simplex and pyorrhoea 
complex. The former he believes is caused entirely by local irritants, the 
latter by constitutional conditions, such as malnutrition, improper elimi- 
nation, uric acid diathesis, etc. 

Kirk (1899), ft recognizing the constitutional origin of the disease, says, 
"It is to the class of non-bacterial inflammatory tissue reactions that 
phagedenic pericementitis in its earlier stages belongs, and that the toxic 
irritant is the group of alloxuric bodies which, like their congener uric 

* Transactions of the American Medical Association, 1891. 

t International Dental journal, vols, xiii., xv., xvi. 

% Ibid., vol. xv. 

§ Dental Pathology, Therapeutics, etc. 

|| Dental Surgery. 

If Dental Cosmos, vol. xl. 
** Dental Review, 1899. 
ft International Dental Journal, vol. xx. 



PYORRHCEA ALVEOLARIS. 537 

acid, are waste products of nitrogenous metabolism, and as a result of 
improper elimination find their way into the blood-stream and thence to 
the membranous investment of the tooth, that are the active causes of de- 
generation of the tissue in question, and, should the irritative influence be 
of sufficient intensity as related to the vital resistance of the elements of 
the membrane, may and do cause its molecular necrosis with attendant 
inflammatory reaction." 

Fitzgerald (1899) * claimed that the production of pyorrhoea alveolaris 
depended upon a constitutional predisposing cause and an exciting cause 
in the form of a local irritation. The predisposing cause might be tuber- 
culosis, syphilis, scurvy, the exhaustion following acute infections diseases 
or any other source of malnurition. The exciting cause is usually a gin- 
givitis induced by several forms of local irritation. He also recognized a 
gouty origin of the disease in which the local necrosis of the pericementum 
is caused by gouty disease of one of the blood-vessels in its substance. 

Talbot (1899) f terms the disease interstitial gingivitis, and says the causes 
are divisible into predisposing and exciting, the predisposing causes being 
again subdivided into local and constitutional. As predisposing factors of 
the disease he mentions conditions of jaw evolution, the transitory nature 
of certain structures, degeneracy, and conditions of previous irritation and 
inflammation. The exciting causes are either constitutional or local, but, 
as a rule, are local or have a local action. He thinks calcic deposits are a 
result and not a cause of the disease. 

Local Origin of the Disease. — Koecker (1821) % regarded the dis- 
ease, which he called inflammation of the gums, as one of local origin, and 
caused by the irritating effects of tartar. He said, "In all the various 
forms of the affection which he had observed he had never seen a case in 
which tartar was not present. . . . Persons of robust constitution are 
much more liable to this affection of the gums than those of delicate 
habit, and it shows itself in its worst form after the age of thirty oftener 
than at any earlier period. 7 ' 

Bromwill (1867) § was of the opinion that the cause of the disease was 
a local one, due to the thinness of the alveolar process between the teeth, 
which deprived the peridental membrane and the gum of proper support. 
Malocclusion of the teeth also exerted an influence by establishing inflam- 
mation. 

Riggs (1875) 1 1 was very emphatic in his opinion that the disorder was 
due entirely to the local irritation of salivary calculus, which was deposited 
at the necks of the teeth just beneath the free margin of the gum, and 
extended from there towards the apex of the root, causing inflammation of 
the gum and peridental membrane, necrosis of the edge of the alveolus, a 
discharge of pus, and recession of the gums. 



* Clinical Journal, March, 1899. 

t Interstitial Gingivitis, 1899. 

X Principles of Dental Surgery. 

§ Dental Cosmos, vol. xxiv. 

|| Transactions of the American Academy, 1875. 



538 OPERATIVE DENTISTRY. 

Shieff (1875),* of Vienna, was of the opinion that the disease had its 
apparent origin in local irritants induced by mechanic, cheniic, and 
thermic changes. The real origin of the disease, however, was often very 
obscure. The influence of the rheumatic diathesis was doubtful. 

Mies (1880) f supported the theory that salivary calculus was the pri- 
mary cause of the disease. But in certain cases there was a constitutional 
condition or diathesis in which there was an excess of phosphates and 
carbonates of lime in the circulation, and this condition exerted an in- 
fluence in the production of the disease. This condition or diathesis was 
probably due to dyspepsia, excessive fatigue, mental or physical overwork, 
protracted illness, or any unusual strain on the system. He thought it 
safe to say that ninety-five per cent, of the cases seen in private practice 
are u due to the deposit locally of lime-salts about rough surfaces on the teeth, 
the nucleus being usually at the point where the enamel joins the 
cementum." 

Walker (1881), % in a paper upon the disorder, expressed the opinion 
that its origin was local, and that the starting-point of the disease was to 
be found in a subacute inflammation of the gum which passed into the 
depths of the alveolar process. 

"Witzel (1882) § regarded the disease as a purely local affection, having 
no constitutional relations whatever. He asserted that the primary origin 
of the disease was an inflammatory condition of the alveolus, accompanied 
by caries of the border and followed by a deposit of calcic material just 
beneath the free margin of the gum, which caused the gingivae to become 
retracted and reverted. The infection of the carious material with micro- 
organisms developed pus, which became infectious to a greater or less 
extent. He therefore termed the disease " infectious alveolitis," and de- 
scribed it as a molecular necrosis of the alveoli, or caries of the dental 
sockets, produced by septic irritation of the medulla of the bone. 

Black (1886), 1 1 in a most exhaustive article, gives it as his opinion that 
pyorrhoea alveolaris is a local disorder. He, however, describes two forms 
of the disease ; one he terms calcic inflammation, the other phagedenic peri- 
cementitis. The former he believed to be due to calcic material deposited 
at the necks of the teeth, which gradually encroached upon the peri- 
cementum, establishing suppurative inflammation, while the latter form 
was characterized by a phagedenic state, — or destructive ulceration of the 
gingiva?, — and destruction of the peridental membrane and alveolar walls. 
He thinks this destructive inflammation of the peridental membrane is 
distinctive from other inflammations of this tissue, and that a serumal cal- 
culus may be associated with its origin. He looks upon the disease as 
having its primary origin in the peridental membrane rather than in the 
alveolus, although the destruction of these tissues apparently goes on 
together. 

* Wiener raed. Presse, vol. xvi. 

f Dental Cosmos, vol. xxiii. 

X Transactions of the International Medical Congress, 1881. 

§ British Journal of Dental Science, vol. xxv. 

|| American System of Dentistry, vol. i. 



PYOERHCEA ALVEOLA RIS. 539 

Talbot (1886) * stated that it was his opinion that the disease was a 
local one, with both local and constitutional causes. He believed the dis- 
ease began as a simple inflammation of the gums which later became 
chronic. 

Sudduth (1894) f offered the suggestion that the principal exciting cause 
of pyorrhoea alveolaris was the lactic acid formed in the mouth by fermen- 
tation. 

Arrington (1900) X takes an extreme view of the origin of the disease, 
and maintains that there is but one form, although there are sundry feat- 
ures that present as the disease progresses. He believes that it is not 
dependent upon any particular state of the system for its origin, for all 
individuals alike, the robust and the feeble, seem to be equally subject to 
it ; nor is it a consequence of, or in any way complicated with, any other 
disease. 

Bacterial Origin of the Disease. — Archovy and Izklai (1881), § in 
discussing Dr. Walker's paper, read at the International Medical Congress, 
London, both ascribed the disorder to parasites or minute organisms. 

Archovy (1884) || shared the opinion of Witzel, that the disease was a 
marginal necrosis of the alveolus, caused by a septic irritation, probably 
the result of minute organisms. He termed the disease caries alveolaris 
specifica. "The nature of the affection is that of a suppurative inflam- 
mation which spreads to all parts lying between the gum and the dentin 
of the root." 

Malassez and Galippe (1884) considered the disease as undoubtedly of 
parasitic origin, " which may be proved by an examination of stained 
sections ; by cultivation and isolation of the parasites contained in the 
dental tubules ; by the contagion spreading from tooth to tooth, as well as 
from individual to individual, as we observed more than once in persons 
of different sex who stand in intimate relations to each other." 

Galippe (1888) ^[ thought he had found the specific organism of the dis- 
ease, which was designated by the Greek letters -q and /?. Galippe 7 s claims 
have not been substantiated by later observation and research. 

Magitot,** in reviewing the labors of Malassez and Galippe, does not 
combat the theory of the parasitic nature of the disease, and concludes 
his remarks with three propositions : 

1. The affection characterized by alveolar suppuration and by loosen- 
ing and falling out of the teeth should be designated as a true sympto- 
matic alveolar arthritis, septic and contagious. 

2. It generally arises under the influence of certain unfavorable con- 
ditions of health and diathesis, also in exanthematic fevers, etc., where it 
manifests itself either as a complication or as a consequence. 

* Dental Cosmos, vol. xxviii. 
f Ibid., vol. xxxvi. 

% International Dental Journal, July, 1900. 
§ Transactions of the International Dental Congress, 1881. 
|| Diagnostik der Zahnkrankheiten, 1885, S. 232. 
\ Die infectiose arthro-dentare Gingivitis, 1888. 
** Miller's Micro-Organisms of the Human Mouth, p. 324. 



540 OPEEATIVE DENTISTRY. 

3. The therapeutics should consist chiefly in the application of anti- 
septics, local alteratives, astringents, or caustics. 

Miller (1890) * was unable to discover any specific micro-organism in 
the pus discharged from cases of pyorrhoea alveolaris. Out of twenty- 
six different cases examined, twenty-two different kinds of bacteria were 
found. In cases 8 and 13, and in 16 and 17, the bacteria were found to be 
identical. He therefore concludes that there is no specific bacterium yet 
found for this disease, as the four cases in which the bacteria were iden- 
tical proved nothing. But if there is such an organism, it will not grow 
on gelatin, and he suggests that in further experiments media should be 
selected which can be kept at the temperature of the mouth. It may be 
possible, however, if such a bacterium exists, that, like many other mouth 
bacteria, it is not cultivable on any of the artificial nutrient media. 

Whittles (1898) f says that in all genuine cases of pyorrhoea alveolaris 
which he has examined he has found in the pus a " particular bacterium 
which is probably of the anaerobic variety." The discovery of this 
organism, which, by the way, is not described, led him to search for an 
efficient antidote, which he found in the "green iodide of mercury," 
triturated in a mortar with a little glycerol to allow of greater readiness 
of application to the sulci or pus pockets of the affected teeth. 

He looks upon the disease as another example of those affections which 
accompany a general lowered condition of the mesoblastic element as a 
predisposing cause, the real excitant being a bacterium. 

Younger (1900) J thinks that Cook has discovered a specific organism 
for the disease, as a certain form was constant in his cultivations. ~No 
definite description is given of the organism, as it was still under culti- 
vation and observation. 

From the foregoing resume of the theories which have been advanced 
to account for the origin of pyorrhoea alveolaris, and the facts which have 
been deduced by observation and experiment, it is evident, that such 
diverse etiologic factors cannot all of them be the real cause of a single 
form of the disease. 

There is no doubt that a considerable number of cases of the affection 
are due primarily to certain acquired systemic conditions, like syphilis, 
mercurialism, iodism, anaemia, dyspepsia, scurvy, malaria, typhoid fever, 
diabetes mellitus, albuminuria, etc., or to inherited disease, like congenital 
syphilis, or to inherited tendencies to diseases like tuberculosis, gout, and 
rheumatism, which induce trophic changes in the tissues and establish a 
predisposition to early senile degenerations ; while, upon the other hand, 
a considerable number of cases are due entirely to certain local irritative 
conditions induced by the formation of salivary concretions deposited at the 
cervices of the teeth and upon the sides of the roots, which by their en- 
croachment upon the pericementum induce inflammation of a suppurative 
character, accompanied in its later stages by ulceration of this membrane, 
disintegration of the alveolar border, and recession of the gum. 



* Micro-Organisms of the Human Mouth. 

f Dental Cosmos, vol. xl. J Ibid., 1900. 



PYORRHOEA ALVEOLARIS. 541 

It is a very doubtful supposition, however, that the disease is ever 
caused primarily by infection of the tissues with the pyogenic cocci, or by 
any specific bacterium. It would seem more probable that the infection 
was a secondary factor or exciting cause, while the primary cause was 
a lowered vitality of the tissues, due to some previous or exciting systemic 
condition, or to injury by local irritants, which had placed the- parts in 
such a condition that they were unable to resist the action of the pyogenic 
micro-organisms which are always present in the mouth. 

The disease may therefore be divided into three general forms, — one 
arising from purely local causes, the others from constitutional or systemic 
conditions, the first of which may be termed, as suggested by Peirce, ' 'ptya- 
logenic calcic pericementitis ;" the second, u hematogenic calcic pericementitis /" 
and the third, u phagedenic pericementitis," as suggested by Black. 

PTYALOGENIC CALCIC PERICEMENTITIS. 

Causes. — This form of the disease has its origin in those systemic and 
local conditions which are thought to produce inflammation of the gums. 
These causes are predisposing and exciting, general and local. Dental 
pathologists are inclined to divide inflammation of the gums into two dis- 
tinct forms, one which is general in its character and termed gingivitis or 
ulitis, and another which is confined to the borders or margins of the gums 
and termed marginal gingivitis. 

Marginal gingivitis is often catarrhal in character, and may be asso- 
ciated with catarrhal stomatitis, and not infrequently precedes ulcerative 
stomatitis. 

In this form of gingivitis ptyalogenic calcic pericementitis is thought 
to have its origin. 

The predisposing causes of marginal gingivitis are general and local. 
The general predisposing causes are those conditions which are associated 
with a faulty metabolism, — conditions which lower the vital resistance of 
the tissues and predispose them to inflammation, suppuration, and various 
degenerative changes. The local predisposing causes are lack of exercise 
and the impaction and decomposition of food debris. The local exciting 
causes are various irritants of a mechanic, chemic, and septic nature, like 
harsh brushing, salivary calculus, irritating drugs, and micro-organisms. 

The presence of a marginal gingivitis, either local or general in char- 
acter, presents the most favorable conditions for the establishment of 
ptyalogenic calcic pericementitis that could possibly be arranged, for by 
the swelling and loosening of the gums at the cervices of the teeth pockets 
or sulci are formed for the lodgement of debris, while the tenacious pro- 
duct of the mucous glands — mucin — acts as a nidus for the formation of 
subgingival deposits, which "are produced by precipitation of the calcic 
material held in solution in the secretions through the action of the 
products of fermentation upon these fluids ;" * and thus the calcic mate- 
rial is deposited in the pockets, and by reason of the fact that it remains 
undisturbed in these locations it accumulates more or less rapidly and 

* Dental Cosmos, vol. xxxvi. 



542 OPERATIVE DENTISTRY. 

becomes very dense. Its peculiar density is due to the fact that it con- 
tains less food debris and leptothrix than the common form of salivary 
calculus. 

Pathology and Morbid Anatomy.— Ptyalogenic calcic pericementitis 
is characterized by the presence of subgingival calcic concretions, dark 
green in color, very hard, and deposited in the form of thin scales upon 
the sides of the roots in open pockets, beginning at the cervix and extend- 
ing in a direction towards the apex. 

The formation of this deposit is doubtless due to a catarrhal condition 
of the mucous membrane of the mouth, resulting in a marginal gingivitis. 
The calcic material is derived partly from the salivary secretions and partly 
from the exudations and abnormal secretions of the mucous membrane and 
the gums. 

The effect of this deposit when once formed is to establish a continuous 
irritation of the margins of the gums, thus keeping up the inflammation 
and exciting degenerative changes not only in this tissue but also in the 
pericementum and alveolar border. 

The existence of a persistent mechanic irritation causes in this case a 
chronic hyperemia of the gum and pericementum, which lowers the vital 
resistance of these tissues and places them in a condition to be readily 
acted upon by the pyogenic micro-organisms which are always present in 
the food debris and mixed secretions of the mouth. 

As a result of the inflamed condition of the margins of the gums they 
become swollen and everted, forming a space, sulcus, or pocket between 
the tooth and the gum, to which the altered secretions, food debris, and 
the saliva have free access. Precipitation of calcic material takes place, 
probably as a result of the products of fermentation coming in contact 
with the fluids of the mouth which hold the calcium salts in solution, and 
thus little by little the concretions are built up. 

Burchard* says, "It is probable that these deposits have their origin 
in a reaction between the altered mucous secretion of the gingival glands 
and the products of lactic fermentation, their calcic salts being derived 
from the saliva." 

The calcic deposits which are found upon the sides of the roots of the 
teeth at remote points from the margin of the gums, but which are in 
communication with the secretions of the mouth through open pockets, 
are productive of great damage to the integrity of the peridental tissues, 
sometimes causing acute diffuse suppurative inflammation and destruc- 
tion of the pericementum, or of chronic inflammation and ulceration of the 
gum and pericementum, with a discharge of fetid pus, necrosis of the 
alveolar border (caries), and resorption of the gum. 

In the first or acute form of this inflammation the process of destruc- 
tion in the tissues is often very rapid, a few weeks or months only being 
required to cause complete exfoliation of the tooth, unless the concretions 
are removed ; and even then the inflammatory symptoms do not always 
subside nor the pockets close, but resist all treatment and remain in a 

* Pathology, Therapeutics, and Pharmacology. 






PYORRHCEA ALVEOLARIS. 543 

state of subacute inflammation, the pericementum thickened, the tooth 
loosened in its alveolus, and gradually extruding or turning upon its axis, 
while it becomes more and more a source of irritation and annoyance to the 
patient until it is extracted or exfoliated. 

In such cases, however, there is always associated with it some peculiar 
systemic condition or dyscrasia, like tuberculosis, syphilis, diabetes, albu- 
minuria, or anaemia, which aggravates the local conditions and retards or 
prevents the healing process. 

In the second or chronic form of the inflammation the process of de- 
struction in the pericementum and the surrounding structures is much less 
rapid and the symptoms are all less aggravated, and whereas in the acute 
form of the inflammatory process the tooth may be exfoliated in a few 
weeks or months, in the chronic form of the disease this process may be 
extended over as many years. A large per cent, of the latter cases are 
amenable to surgical treatment, and these are the cases of pyorrhoea alveo- 
laris which are so often advertised as cured. The cause of irritation is a 
purely local one, — a mechanic irritant ; therefore when the cause is removed 
and the parts are assisted in the healing process a cure takes place. 

In many of the remaining smaller per cent, of cases, which do not 
readily respond to treatment, there is often a history either of gout, rheu- 
matism, malaria, anaemia, leukaemia, nephritic diseases, physical, nervous, 
or mental debility, reflex neurosis, or in married females of frequent preg- 
nancies or prolonged lactations. Sometimes local conditions are present 
which produce over-stimulation or under-stimulation of the circulation 
of the pericementum, like malocclusions of the teeth, or loss of occlusion, 
which would in the one case predispose them to hyperemia and inflamma- 
tion of the pericementum, and in the other to atrophy, thus lowering the 
vital resistance of the tissues and preparing the way for the destructive 
action of the pyogenic micro-organisms. 

The individuals who are the most liable to suffer from this form of 
pyorrhoea alveolaris usually possess teeth of finely organized structure, 
which are very resistant to cutting instruments and singularly free from 
dental caries. These facts were noticed by the earliest writers upon the 
disease, and were classed by them as predisposing etiologic factors, as it was 
thought that their density and consequent low vitality predisposed them to 
exfoliation when attacked by inflammatory disease of the root. 

Harris* says, "It may also be produced by very hard teeth which, in 
consequence of their density, possess only a very low degree of vitality ; 
for cases of recession of the gums, in which a very slight inflammatory 
action exists, are frequently met with in individuals having teeth of this 
description. This can only be explained by supposing a want of congeni- 
ality between these organs and the more sensitive and highly vitalized 
parts with which they are in immediate contact." 

On making sections of these teeth, the enamel and dentin are found to 
be exceedingly hard and much more translucent than the average tooth. 
The pulp-chamber is usually considerably contracted, the pulp often show- 

* Harris's Dental Surgery. 



544 OPERATIVE DENTISTRY. 

ing evidences of calcification, atrophy, and other senile changes. In the 
later stages of the disease the vitality of the pulp is often destroyed by the 
intense inflammation of the tissues of the apical space, the swelling pro- 
ducing pressure upon the pulp-vessels. 

An examination of the root reveals the fact that the pericementum is 
greatly inflamed or undergoing degenerative changes (Fig. 624), or has 
been destroyed to a greater or less extent according to the character and 
stage of the disease when the tooth was removed. Wherever tophi (con- 
cretions) have formed upon the root the pericementum will be missing, 
not only upon that portion of the root covered by the deposit but for 
a considerable area beyond ; this is a constant condition. It not infre- 
quently happens that the pericementum will be destroyed upon one side 
of the root from the cervix to the apex while it will be intact over the 
remaining surfaces ; or it may be destroyed upon all sides but one ; 
and, again, the process of destruction may encircle the tooth for an equal 
distance upon all sides. The latter condition is most often associated 
with the anterior teeth, and especially when the tooth has no immediate 
neighbors. 

As the disease progresses the teeth become more and more loosened in 
their alveoli, until finally they drop out or have to be extracted to relieve 
the intense soreness which is developed as a result of their mobility and 
frequent injuries due to their elongation and malocclusion. 

In cases of long standing a secondary form of deposit is often observed 
upon the roots of these teeth. The primary deposit is formed in thin 
scales just beneath the gum margin ; the secondary is formed beyond the 
primary deposit, upon the denuded cementum, in those locations which 
are constantly bathed in pus. The secondary deposits are so different in 
appearance that they cannot be mistaken for the primary deposit ; for, in- 
stead of being formed in thin scales with an even surface, they are formed 
either in tiny bead-like islands or in larger masses with bead-like projec- 
tions upon the surface, and very similar in appearance to the concretions 
formed upon bodies, either animal or mineral, that have been lodged in 
the tissues and bathed in pus for a considerable period of time. Such 
deposits are frequently seen upon the apical portion of the roots of teeth 
which have been the subject of long-continued chronic alveolar abscess. 
They are, therefore, not the primary cause of the disease, but the result 
of chronic inflammation and deposition of calcareous material from the 
inflammatory products. 

Symptoms and Diagnosis. — The first symptom of the disease in its 
early stages is usually inflammation of the margins of the gum, — marginal 
gingivitis, — which are turgid and reddened, the tips of the festoons often 
being of a purplish color. 

The extent of the swelling and discoloration will depend upon the 
severity of the inflammation and the diathesis of the individual. The 
gums bleed readily upon the least friction or rough usage. The margins 
of the gums are slightly everted, and the sulci or pockets formed between 
the margins of the gums and the cervices of the teeth are filled with food 
debris and thickened mucous secretions, or a thick, cheesy mass of material 



; • - ; ' :-'*■■■■■; \ >.>. ' vv. 





Fig. 624. — Inflamed peridental membrane from a case of pyorrho?a alveolaris. 50. 



PYORRHCEA ALVEOLARIS. 545 

made up of these substances and epithelial scales, numerous forms of bac- 
teria, and calcic material. 

Later in the history of the case, if an instrument is passed beneath the 
margins of the gum, a scaly deposit of dark-green calculus will be found 
adherent to the cervix of the tooth. This may be upon one surface only, 
or it may encircle a larger portion or the whole of the cervix. 

Occasionally, however, cases will present in which the deposit seems 
to have occurred before the marginal gingivitis was developed, and that 
the deposit was the cause of the gingivitis. These cases may have their 
origin in cervical deposits, which later develop a chronic marginal gingivitis, 
as already described in the preceding chapter, or it may be that the inflam- 
matory condition of the gum has subsided after the formation of a com- 
paratively smooth calculus. 

As the formation of the calculus progresses it encroaches upon the 
periosteum, causing inflammation and ulceration of this membrane. The 
constant presence of the pyogenic bacteria in the mouth affords the means 
of septic infection, which attacks the tissues as soon as they can gain an 
entrance to them through an abraded surface or other break in their con- 
tinuity. As a result pus is formed, which may be pressed from beneath 
the margins of the gums. An examination of the margins of the alveolus 
with a fine probe will sometimes discover these edges eroded by caries, but 
more often they will not be found uncovered, the process of destruction 
seeming to be one of resorption rather than molecular disintegration by 
caries. In the former cases the odor of the pus is very offensive and dis- 
agreeably taints the breath. 

As the disease advances the pericementum and the alveolar process are 
progressively destroyed, and the gum gradually recedes as this process 
continues, until the tooth becomes very loose in its alveolus. The increased 
mobility, elongation, and the malocclusion incident to these conditions 
excite inflammatory action in the tissues beyond the field of the original 
disease, thus increasing the soreness and discomfort of the tooth. 

In some cases, at this stage of the disease, hypersemia of the pulp may 
be developed, followed by embolism and death, or the inflammation and 
cedema of the apical tissues may be so great as to cause strangulation of 
the vessels of the pulp at the apical foramen. As a result of the devitali- 
zation of the pulp and septic infection, the case may now be complicated 
with a septic apical pericementitis. 

The termination of the disease is in the exfoliation of the tooth. All 
inflammatory symptoms immediately subside upon the loss of the tooth, 
and the gums and alveolar border assume in a very short time a healthy 
appearance. 

Prognosis. — The prognosis is favorable, even in the later stage of the 
disease, provided the exciting causes can be removed and the constitutional 
predisposing causes, when they exist, corrected. 

Treatment. — In the treatment of ptyalogenic calcic pericementitis 
there are two main objects to be considered. The first is the removal of 
all sources of irritation, and the second is supporting the diseased teeth so 
as to secure surgical rest during the healing process. 



546 



OPERATIVE DENTISTRY. 



The removal of the sources of irritation comprehends all forms of local 
and constitutional irritants. The principal local irritants are the calcic 
deposits, food debris, and septic bacteria. The removal of the deposits is 
a surgical procedure, and requires special instruments for its success. 

Instruments of an entirely different form are required in the removal of 
the subgingival salivary deposits from those employed in removing the ordi- 
nary forms of salivary calculus. 

The most important desiderata in the instruments used for the purpose 
of removing the deposits from the sides of the roots beneath the gums are, 
first, that they shall be so thin that they will pass readily into the pockets 
formed in the alveolar wall between the root of the tooth and the gum ; 

Fig. 625. 




After Burchard. 



second, so flexible or springy that when the flat side of the instrument is 
laid against the side of the root a lateral and downward pressure will cause 
the instrument to glide over its surface, removing any concretions that 
may be thereon, but not cutting into the cementum. 

These hard salivary concretions are most readily removed or scaled from 
the surface of the root by driving or pushing the instrument from the 
margin of the gum towards the apex of the tooth, keeping the flat side of 
the instrument always in contact with its surface. For this purpose chisel- 
shaped instruments only should be used. Fig. 625 shows the manner of 



PYORRHCEA ALVEOLA RIS. 



547 



holding the instrument, and Fig. 626 the application of the instrument to 
the root of the tooth. 

Some operators, however, prefer instruments which can be used with a 
drawing motion, the cutting end of which is made like the hoe excavator, 
hut with the blade much shorter. This of course makes 
the instrument bulky at its cutting end, and prevents Fig. 626. 

it from being carried as near to the apex of the root as 
is possible with the thin chisel-shaped instrument ; hence 
there is not the same certainty that the concretions are 
all removed in the farthest limits of the pockets as would 
be the case if the chisel-shaped instruments were em- 
ployed. The instruments best suited to this purpose are 
the Allport and the Gushing scalers (Figs. 627 and 628). 

The importance of the thorough removal of every 
particle of the deposit from beneath the gums cannot be 
over-estimated. Many failures to arrest the inflamma- 
tory symptoms in these cases can be traced to the fact 
that some small particle of adherent deposit has not been After Bmchard. 
reached. 

The operation even under the most favorable circumstances presents 
many obstacles and difficulties, which can only be overcome by those opera- 
tors whose sense of touch has become so acute as to be almost the equal of 
vision. The six anterior teeth of both jaws present the most favorable 
conditions for the successful removal of such concretions. These difficul- 
ties, however, are greatly increased in the bicuspids and the molars by their 




Fig. 627. 




Allport's pyorrhoea alveolaris instruments. 



more inaccessible location, by their shape, and the number of their roots. 
The most difficult problem is the removal of the deposits from the bifur- 
cations of the roots and from the surfaces of the roots which look towards 
each other. 

After the concretions have all been dislodged from their attachment to 
the root, the pockets should be injected with a drop or two of hydrogen 
dioxide (H 2 0. 2 ) by the use of the Dunn medicinal drop syringe (Fig. 629), in 



548 



OPERATIVE DENTISTRY. 



order to free the pockets from all calcareous debris ; after which they may 
be treated by the application of aromatic sulphuric acid, lactic acid, 
trichloracetic acid, or a saturated solution of iodine crystals in beech- 
wood creosote. Various other remedies are employed for the treatment 
of the pockets, but the mention of these is sufficient to indicate their 
character. 

The after-treatment consists in the free use of antiseptic mouth- washes 

Fig. 628. 




Ill 



Cushing's pyorrhoea alveolaris instruments. 

and painting the gums with equal parts of tincture of iodine and tincture 
of aconite every other day for a week or ten days. 

The writer has for many years been in the habit of employing an 
atomizer for applying the antiseptic lotions or mouth- washes in the treat- 
ment of these oral conditions. The patient is instructed to thoroughly 
brush the teeth after each meal, then to pass floss-silk between all of the 
teeth, and follow this cleansing process with the atomizer, using sufficient 
force to drive the antiseptic fluid through the interdental spaces. If by 
the end of a week the gums have not assumed their normal color, or there 
is still a discharge of pus from any pocket, the chances are that a small 
adherent scale of calculus still remains. This should be searched for and 
removed and the case treated as before. In all of those cases that are 



Fig. 629. 




Dunn medicinal drop syringe. 

complicated with systemic disorders which predispose to pericemental 
degenerative changes, attempts should be made through the family medi- 
cal adviser to correct these conditions. 

Local treatment under such circumstances, although it may prove help- 
ful in relieving immediate suffering and placing the mouth and teeth in 
a more hygienic condition, will not prove curative until the constitutional 
dyscrasia is improved. 



PYORRHCEA ALVEOLA RIS. 



549 



Surgical Rest. — Teeth which have become much loosened by reason 
of the resorption of the alveoli must be given surgical rest if the healing 
process is to be successfully completed. This rest may be secured by sup- 
porting the teeth, either by ligatures of silk or linen attached to contiguous 
teeth, or by wire, either of gold or silver, or by splints made of gold or 
platinum and cemented to the teeth. 

These splints (Fig. 630) are most readily made by fitting thirty-four 
to thirty-six gauge bands to the individual teeth, taking an impression of 
them in situ, investing, and soldering the whole together. 



Fig. 632. 



Fig. 631. 



Fig. 630. 



Splint prepared. (After 
Burchard.) 




Labial view of splint in po- 
sition. (After Burchard.) 




Lingual view of 
splint in position. 
Burchard.) 



Fig. 631 shows this splint after it has been cemented in position. Or an 
impression may be taken of the teeth after they are supported with silk 
ligatures, and a splint swaged from gold or platinum and cemented in 
place, as shown in Fig. 632. 



CHAPTEE XXXIX. 

HEMATOGENIC CALCIC PERICEMENTITIS. 

This form of pyorrhoea alveolaris is found most frequently in persons 
suffering from certain peculiar inherited or acquired constitutional condi- 
tions, — viz., rheumatic and gouty affections, or, in other words, the ar- 
thritic diathesis, and for this reason it has been termed by some writers 
gouty pericementitis. 

Magitot (1867), as stated in the preceding chapter, called attention to 
the fact that in his opinion persons of the gouty and rheumatic diathesis 
furnished the greatest number of cases of pyorrhoea alveolaris. Reese 
(1886) pointed out most clearly the association of this disease with the 
gouty diathesis. The writer (1891) demonstrated the analogy between the 
gouty deposits and the degenerations of the fibrous tissues of the joints 
and certain pericemental degenerations, and suggested that certain deposits 
were found upon the roots of the teeth in locations which had no com- 
munication with the salivary secretions, and that these concretions were 
deposited from the elements of the blood, and were composed of the urates 
of lime and soda. Peirce (1892-94-95) has proved by careful experiments 
the truth of the above suggestions of the writer in relation to the location 
of these deposits and their composition. 

The demonstration of the fact by Dr. Peirce that the deposits found 
upon the roots of the teeth in these locations gave the murexid reaction 
proved conclusively that they contained biurates, the same as found in 
the gouty concretions in other portions of the body. The establishment 
of this fact gave a great impetus to the study of the association of this 
disease with the gouty diathesis. The result of this study, however, in 
certain directions, through a misunderstanding of the premises laid down 
by the advocates of the theory, has been to throw doubt upon the correct- 
ness of their conclusions. The teeth that have been used in these studies 
by the opponents of this theory have admittedly been taken in great 
quantity, hap-hazard, from the scrap-box of the professional extractors, 
which made it impossible to obtain the history of a single case ; neither 
could there be any means of knowing whether the concretions used for the 
chemical analyses were deposited from the saliva in open pockets or from 
the elements of the blood in locations where the secretions of the mouth 
could not have come in contact with them. 

These are important distinctions, and if they are observed in future 
researches upon this subject they will give the same results as those 
obtained by Peirce and the other advocates of this theory. 

Predisposing Causes. —The predisposing causes of this form of 
pyorrhoea alveolaris (gouty pericementitis) are those conditions of the sys- 
tem which are designated as the gouty and rheumatic affections. Gouty 
pericementitis, however, is only a local manifestation of this general mor- 



HEMATOGENIC CALCIC PERICEMENTITIS. 551 

bid state of the system, which is due either to imperfect metabolism (sub- 
oxidation and faulty elimination) or to an excessive formation of uric acid, 
resulting in the accumulation within the system of an abnormal amount of 
certain waste products termed the urates. Individuals who are thus affected 
are said to possess the uric acid or gouty diathesis. It must be remembered, 
however, that lead-poisoning resembles gout in giving rise to an excess of 
uric acid in the blood. 

Urates are always found in excess in the serum in instances of deficient 
oxidation, arthritis, and valvular diseases of the heart. They are also 
found in the urine, as, for instance, in a case of phthisis where an insuffi- 
cient amount of oxygen is absorbed, oxyhemoglobin is deficient, and conse- 
quently many of the normal transformations of the body are completely or 
partially arrested. In such cases quantities of oxalate of lime will be 
found in the urine, the carbon of the food and of the waste material from 
the tissues is only partially oxidized, and that which should have been 
exhaled from the lungs as carbonic acid is excreted by the kidneys as 
oxalic acid. Again, in the condition of venous stasis arising from feeble 
action of the heart the blood stagnates in the veins, becomes loaded with 
poisons, is not carried to the lungs with due rapidity, and those nitrogenous 
parts of food and tissue which normally are converted into, and excreted 
as, urea appear in the urine as uric acid, free or combined. (Vaughn.) 

A persistent excess of uric acid in the urine is, therefore, always con- 
sidered as a significant symptom of an important systemic condition, due 
to an increase in tissue metabolism in some particular organ or group of 
organs. 

Heredity. — The gouty diathesis is usually inherited, and the active 
manifestations may be induced in such individuals by high living or by the 
deprivations of extreme poverty. 

Gairdner and Garrod state that in about ninety per cent, of all persons 
suffering from gout, the disease also existed in their forefathers. Peirce is 
of the opinion that in gouty pericementitis fully ninety per cent, manifest 
an hereditary tendency to the disorder. 

Gout diminishes the powers of resistance against disease and injuries, 
especially when the kidneys and the liver are affected. Many gouty indi- 
viduals, however, live to an advanced age. 

Diet. — The excessive use of foods containing large quantities of nuclein 
or saccharine substances, and the use of alcoholic beverages, particularly 
fermented liquors, are predisposing causes of gout, and also of this form 
of pyorrhoea alveolaris. 

Sex. — Sex does not seem to play a very important part in the predis- 
position to pyorrhoea alveolaris in general. Men, however, are much more 
subject to gout than women, and as a natural consequence to gouty perice- 
mentitis. 

Age. — Gouty manifestations may appear at any period of life from 
infancy to old age. It is most common, however, after middle life. This 
is true also of gouty pericementitis, although cases have been recorded as 
occurring before the age of puberty. 

Magitot and Peirce both agree that this form of pyorrhoea is most 



552 OPERATIVE DENTISTRY. 

frequent between the ages of thirty and fifty years, and that it rarely 
appears after the age of sixty. 

Occupation. — Sedentary occupations are important predisposing causes 
of gouty pericementitis, as they favor imperfect oxidation of the food, 
faulty metabolism, and retard the elimination of the waste products. Sys- 
tematic exercise in the open air tends largely to counteract these faults in 
the functions of the body. 

This morbid state of the system, known also as tiricacidcemia or uricaemia, 
finds expression in a multitude of ailments and abnormal conditions of 
various tissues and organs, some of which are acute, others chronic, in 
their manifestations. 

Blood-Vessels. — Various functional and organic changes are found in 
the blood-vessels of gouty subjects, such as dilatation of the aorta, thick- 
ening of the walls of the arteries, loss of elasticity, atheroma, and even 
calcification. Phlebitis is a well-recognized gouty ailment, which may 
produce thrombosis, and by dislodgement of the clot cause sudden death 
by impaction in the heart, pulmonary artery, or lungs. 

Circulation. — The effects of uricacidaemia upon the circulation, as 
pointed out by Haig, are to produce l ' contraction of the arterioles, and thus 
increase arterial tension." When these conditions affect the cerebral 
circulation they result in headaches, mental depression, fatigue, irrita- 
bility of temper, hysteria, vertigo, epilepsy, and convulsions. 

Asthma and chronic bronchitis are often the result of the effect of uric 
acid upon the pulmonary and bronchial circulation, and seem to explain 
the association so often noticed between these affections on the one hand, 
and gout and chronic Bright's disease upon the other. 

Dyspepsia may undoubtedly be produced by the contraction of the 
arterioles of the stomach and intestines, thus inhibiting gastro-intestinal 
digestion and permitting putrefactive processes to take their iriaee, which 
would explain the association between dyspepsia and such affections as 
sick-headache, mental depression, fatigue, epilepsy, etc., or the relation- 
ship between dyspepsia and Eaynaud's disease or paroxysmal haemo- 
globinuria. 

The liver is subject, also, to more or less congestion as a direct or in- 
direct result of circulatory changes produced by uric acid. 

Blood. — The blood itself is changed in a greater or less degree by the 
action of uric acid, both in its structure and its nutritive power. The 
presence of uric acid in the blood reduces the percentage of haemoglobin 
and the number of red corpuscles, thus producing anaemia. Haig was 
able to increase or diminish the amount of haemoglobin and the number 
of red corpuscles in his own blood from day to day by the administration 
of iron and uric acid respectively. The amount of uric acid in healthy 
blood is so small that it is with extreme difficulty that it can be detected. 
Garrod has demonstrated the fact, however, that in gout the blood is espe- 
cially rich in uric acid, and has found as high as 0.175 parts in 10,000, and 
that the blood is especially charged with it just prior to and during acute 
attacks, but that it is always present in chronic gout. 

Eoberts claims, however, that uric acid as such is never found in the 



HEMATOGENIC CALCIC PERICEMENTITIS. 553 

blood or deposited in the tissues, but that as normally found in the blood 
it is in the form of a quadrurate, a compound of four equivalents of uric 
acid with one of soda or potash. This quadrurate is an exceedingly un- 
stable compound, and under especial conditions is liable to be decomposed 
into biurate and uric acid. The tophi of gout consist of the biurate, but 
this salt is almost insoluble in serum ; even at body temperature it is 
dissolved only in the proportion of 1 in 10,000. (Levison.) 

The tophi are formed by the transformation of the quadrurates found 
in the blood into biurate and uric acid, which gives rise to the deposition 
of the former compound in various tissues of the body, while the uric acid 
is eliminated by the kidneys. The tophus formed from this crystalline 
deposit of sodium biurate "acts passively and physically as a foreign 
body in the affected tissue or organ." (Luff.) 

Tunnecliffe and Bosenheiin* combat the claim of Eoberts of the ex- 
istence in the blood of uric acid in the form of quadrurates. They con- 
cede, however, the existence of two classes of uric acid salts, the neutral 
(C 5 H 2 N 4 3 )M and the acid or biurate (0 5 H,I 4 O 3 )HM. They conclude 
that there is no evidence of the existence of quadrurates, that the term 
should be abandoned, and that any theory concerning the pathology or 
treatment of gout built upon this assumption requires revision. They 
think the existence of two forms of uric acid (the tantomeric lactam and 
lactim forms) may explain the variation in the physic and physiologic be- 
havior of this acid and its salts. 

Molliere has demonstrated the fact that uric acid and the urates are 
antagonistic to the development of the pyogenic micro-organisms. This 
explains the reason why suppuration so seldom occurs about tophi, other than 
those located upon the roots of teeth. 

Duckworth found the red corpuscles diminished and the leucocytes 
somewhat increased in those cases already affected with chronic ne- 
phritis. 

The amount of urea found in the blood in all cases associated with 
granular kidney disease doubtless depends upon the degree of renal in- 
adequacy. 

Garrod frequently found oxalic acid in the blood of gouty subjects ; he 
believed its formation occurred principally in the paroxysmal stages, and 
that it was derived by oxidation from the uric acid. 

Ebstein discovered that xanthin and hj^poxanthin were formed in the 
blood drawn from gouty subjects upon exposing it in a warm chamber, 
while minute quantities of uric acid disappeared. 

Secretions.— During attacks of uric acid headaches the urine and the 
salivary secretions are diminished, the mouth and tongue often being dry 
and parched ; in chronic gout this dry parched condition may last for 
months, but in acute gout, as soon as the excess of uric acid has been 
eliminated from the blood by the administration of appropriate remedies 
and the blood has assumed a normal alkalinity, the secretion of urine and 
of the oral fluids becomes for a time relatively excessive. The saliva often 

* London Lancet, June 16, 1900. 



554 OPERATIVE DENTISTRY. 

shows a decided acid reaction during attacks of acute gout, and usually 
gives a slight acid reaction in chronic gout. 

The amount of urea excreted in the urine, according to Garrod, is about 
three hundred and twenty grains per diem. Few analyses have been made 
of the excretion of urea in acute gout, but such as have been recorded 
show no material variation from the normal amount. The variation, how- 
ever, such as exists, bears no relation to the amount of uric acid excreted 
at the same time. (Garrod.) The excretion of urea is diminished just 
before an acute attack of gout. 

Haig gives the relation of urea to uric acid in the healthy adult as one 
to thirty-three, and says that in uric acid headache the excretion of urea was 
practically unchanged, while that of uric acid fluctuated greatly, particu- 
larly in relation to the headaches. Granville's examinations of the urine 
of gouty subjects corroborate the records of Haig. 

The non-elimination of uric acid has been demonstrated by Garrod to 
be a constant and marked feature of paroxysmal gout. He found in several 
cases examined in reference to this point that the average amount was 
about five grains less than the normal,— 3.62 grains as against 8.569 grains. 
As a consequence of its non-elimination by the kidneys there is an in- 
creasing amount stored up in the blood or the tissues of the body. Haig 
is of the opinion that much of this may be stored in the liver and the 
spleen. 

The greatest amount of excretion in health occurs during the alkaline 
tide of digestion. (Eoberts. ) It is probable that the excretion of uric acid 
in gout, could it be watched from hour to hour, would be found to vary 
considerably. (Duckworth.) 

Sansone,* in analyzing one thousand grains of morning urine in a case 
of acute gout, found 0.830 grain of uric acid ; in one of chronic gout, 0.120 
grain ; and in a healthy person, 0.250 grain. 

Gouty individuals often suffer from gravel and calculosis ; oxaluria is 
not uncommon, while chronic cystitis and urethritis are occasionally ob- 
served in elderly persons suffering from gout. 

Kidneys.— The morbid changes which are found in the kidneys of 
gouty subjects present the ordinary signs of granular atrophy, and cannot 
be distinguished from it either by the symptoms or by an examination of 
its anatomical structure. The relationship between chronic Bright' s dis- 
ease and certain features of uricacidsemia is so constant that many observers 
have been led to believe that the disease was caused by imperfect meta- 
bolism of the albumins, and possibly as the result of the presence of an 
excess of uric acid in the system. 

Duckworth f is of the opinion that the gouty habit is alone the potent 
factor in a considerable proportion of all cases of interstitial nephritis. 

Ord and Greenfield, % in a large series of cases examined with the object 
of determining the presence or absence of renal disease in gouty subjects 



* Beale, Urine and Urinary Deposits, 2d edition, p. 162. 

t Treatise on Gout, p. 101. 

X Transactions of the International Medical Congress, 1881. 



HEMATOGENIC CALCIC PERICEMENTITIS. 555 

with uratic deposits, found that in 66.66 per cent, of the hospital cases of 
gouty affection of the metatarso-phalangeal articulation of the great toe 
there was a definite coexistence of contracted granular kidney, and that in 
the remaining 33.33 per cent, there were affections of the kidneys closely 
allied thereto. Out of ninety-six cases of renal disease, there were eight 
and possibly nine in which no uratic deposits were found in the joints. 
Of these, two were examples of extreme granular contraction, two of 
marked contracted granular, two of slightly granular, and one of mixed 
granular and tubular nephritis. 

Moore * examined forty-nine cases of chronic interstitial nephritis in 
males, and found uratic deposits in twenty-two. In another series of six- 
teen females, uratic deposits were present in five cases. 

Continental European physicians generally hold the opinion that uratic 
deposits are constantly found in the contracted kidneys of gouty subjects, 
and that this condition is somewhat dependent upon the presence of such 
deposits. Duckworth's studies do not corroborate this opinion, as he rarely 
found such deposits in the kidneys of the gouty. 

Liver. — Haigf is of the opinion that the hyperemia or congestion of 
the liver always present in diabetes is due to the same cause that produces 
this condition of the liver in gouty dyspepsia, — viz., the presence of an 
excess of uric acid in the blood. 

Ord X has pointed out the fact that general high arterial tension may 
cause an excess of blood in the liver, and thus produce diabetes ; while 
Haig § has shown that the contracted arterioles and arterial tension are in 
a direct ratio to the amount of uric acid circulating in the blood, and the 
so-called " liver attacks" he looks upon as uric acid storms, almost if not 
quite identical with attacks of uric acid headaches. 

Diabetes seemingly holds a close relationship to gouty conditions, and 
must be dependent upon some error of metabolism for its existence. Both 
of these conditions present many similar symptoms. Latham || observed 
"that diabetic individuals often have an excess of uric acid in their urine 
and suffer from neuralgic pains in the joints and limbs." 

Anderson ^[ observed "many clinical facts which seem to prove that 
gouty arthritis and diabetes mellitus are in certain cases merely trans- 
formed symptoms of the same diathesis ; not present at the same time, but 
one taking the place of the other." 

Garrod ** noticed this relationship, and says, ' ' In the course of practice 
I have seen several cases in which gouty patients have become affected 
with saccharine diabetes or glycosuria. In one case of gout of twelve 
years' standing, in a gentleman sixty years of age, diabetes suddenly de- 
veloped, and for a period of over four years there were no more attacks 

* Loc. cit. 

f Uric Acid the Causation of Disease, p. 287. 
J British Medical Journal, 1889. 
§ Uric Acid the Causation of Disease, p. 272. 
II Ibid. 

i British Medical Journal, 1886. 
** Ophthalmic Review, 1889. 



556 OPERATIVE DENTISTRY. 

of the gout. But when the diabetes was checked the gout very soon re- 
turned. ' ' 

Muscles. — Although no morbid changes have been observed in the 
muscular system in uricacidaeniia, uric acid has often been found in these 
structures. 

Uricacidaemia produces, probably through depression of the nerve-cen- 
tres, a disinclination to muscular exercise during gouty attacks ; this re- 
sults in a deficient circulation in the muscles, and consequently in imper- 
fect elimination of the waste products. The tendons become involved in 
association with the joints and uratic deposits are formed in them. The 
muscles often become the seat of neuralgic pains, which come and go with 
other gouty symptoms. 

Nervous System. — So far no morbid changes have been discovered in 
the anatomical structure of the nerves of gouty subjects except those due 
to cachexia in cases of* long standing. Uratic deposits are rarely found in 
the nerve-tissues or their investments. Cornil discovered sodium urate in 
cerebro-spinal fluid, and uratic deposits have been detected in a few in- 
stances in the cerebral meninges. 

Albert and Ollivier also found such deposits on the spinal meninges. 
There are strong clinical reasons for believing that uricacidaemia may in- 
duce neuritis in almost any nerve-trunk, with motor, sensory, and vaso- 
motor symptoms. (Duckworth.) Neuralgia is a common affection in 
gouty individuals. Sciatica and general myalgia are not infrequently 
associated with other gouty symptoms, and the writer has seen several 
cases of trifacial neuralgia which were undoubtedly due to gout. 

Skin. — The circulation and the nutrition of the skin are often markedly 
affected by the presence of an excess of uric acid in the system, which are 
manifested during uric acid headaches in a pale, cold condition of the sur- 
face of the skin, and in certain eruptive diseases, particularly those of an 
ulcerative character. Among the diseases allied to gout may be mentioned 
erythema, eczema, urticaria, psoriasis, prurigo, and acne. (Sarjou.) Gold- 
ing-Bird discovered uric acid in the contents of the vesicles of gouty 
eczema, and Begbie found it in the bullae of pemphigus. 

Ulceration of the skin and suppuration often accompany the exfolia- 
tion of the tophi located about the joints. 

Periosteum and Bone. — Uratic deposits frequently occur in the peri- 
osteum, resulting in inflammation and sometimes in exfoliation or extru- 
sion of the deposit. On the other hand, inflammatory symptoms are often 
present in and about the epiphyses of the long bones, particularly of the 
legs, feet, and hands, which result in the formation of nodes or of a true 
exostosis. The thickening of the edges of the alveolar processes so often 
seen associated with gingivitis is usually the result of chronic irritation 
or inflammation of the periosteum of these parts due to the gouty diathesis. 

Nails. — These tissues are dermal appendages, and are therefore more 
or less profoundly affected by all diseases which have a predilection for 
dermal structures. In gouty individuals the nails are observed to be coarse, 
fibrous, and brittle, striated, fluted, and lined vertically. 

After an acute attack of gout depressions or white spots or lines are 



HEMATOGENIC CALCIC PERICEMENTITIS. 557 

observed, forming crescent-like curves, which points to faulty nutrition, 
and, inasmuch as the nail requires six months in which to complete its de- 
velopment, these defects, by their position, would indicate the date at 
which the illness occurred, just as faults of nutrition are recorded upon 
the enamel of the permanent teeth, and indicate by their location the age 
of the individual when the illness occurred. 

Hair. — Senile changes occur earlier in certain tissues than in others. 
These tendencies may be acquired as the result of disease or of debauchery, 
or they may be inherited as a family peculiarity, or an evidence of de- 
generacy. 

This tendency to early senile change is particularly noticed in refer- 
ence to the hair. In some individuals the hair turns gray at or before the 
thirtieth year, while in others distinct baldness may occur at an equally 
early age. These conditions are often noticed to be associated with the 
gouty diathesis, and in some instances are no doubt dependent upon 
uricacida3mia as a primary factor in its causation. " The hardened tophace- 
ous matter sometimes found in the sebaceous glands of gouty subjects is 
composed largely of urates. About fifty per cent, of it is sodium and cal- 
cium salts of uric acid, about ten per cent, sodium chloride, and the re- 
mainder calcium phosphate and animal matter." (Duckworth.) 

Teeth. — The character of the teeth in gouty subjects is remarkable in 
that, as a rule, they are well formed, finely developed, having strong, hard 
enamel, which is inclined to a yellowish color ; they have strong roots 
which are firmly set in their alveoli, and are comparatively immune to 
caries. After middle life they are inclined to show considerable wear 
upon the morsal surfaces. This has been thought to be due to the habit 
of grinding the teeth which is so common with rheumatic and gouty indi- 
viduals. This habit is doubtless formed as a result of irritation and hyper- 
emia of the pericementum so constantly present in chronic gout. Neu- 
ralgic pains are also frequently present, and come and go with other gouty 
symptoms. The teeth, like the hair, often show evidences of early senile 
changes. The pericementum and the alveolar processes atrophy and are 
resorbed, while the gums gradually recede as the former conditions pro- 
gress until the teeth become loose and fall out. These changes often begin 
before middle life is reached, and when these tendencies are associated 
with a gouty diathesis the destructive process becomes most marked and 
rapid in its progress. 

Exciting Causes. — The immediate exciting cause of gouty pericemen- 
titis is undoubtedly the presence of uratic deposits in the pericemental 
membrane. This morbific material plays the part of a foreign body, and 
causes mechanical irritation and death of the surrounding cellular ele- 
ments, — necrobiosis, — which favors the further deposition of the urates. 
The inflammatory process does not always progress to the suppurative 
stage, as infection with the pyogenic cocci is necessary for the establish- 
ment of a septic inflammation. 

Impaired nutrition of the pericementum with its consequent lowered 
vitality is also an important factor in the establishment of the disease. 
These conditions are to be found as a result of severe mechanical strain 



558 OPERATIVE DENTISTRY. 

from over-exercise of the teeth, — misuse, — as in malocclusion and the loss 
of the teeth, which places the strain of mastication upon a few remaining 
teeth ; in insufficient exercise of the teeth — disuse — from various causes, 
as, for instance, loss of occlusion, the constant use of soft, pulpy foods 
which require little mastication to comminute their substance ; overcrowd- 
ing of the dental arch ; traumatic injuries consequent upon wedging, mal- 
leting, changing the position of certain teeth in the process of regulating, 
and other similar procedures. The unskilful or immoderate use of the 
tooth-pick, floss-silk, and the toothbrush may occasionally induce con- 
ditions of irritation which impair the nutrition of the pericemental 
membrane. 

Varieties. — In gouty pericementitis two forms of inflammation may 
be observed, — one which produces a new growth of cementum, or hyper- 
cementosis, and another which results in a deposition of calcic material 
combined with sodium biurates from the elements of the blood. The 
former variety has already been described in the preceding chapter on 
" Pericementitis." The latter variety is that condition which has been 
classed by Peirce, Darby, Burchard, Jack, and others as gouty pericemen- 
titis, and which the writer has described as a local manifestation of the 
gouty diathesis, in which tophi are formed within the pericementum, and 
upon the surface of the cementum in closed pockets, and in various loca- 
tions more or less remote from the cervix and at the apex. ' ' These tophi 
are composed of sodium and calcium biurates, free uric acid, and calcium 
phosphate, as has been demonstrated by careful analysis." (Peirce.) 

The manner in which these tophi are formed within the pericementum 
is as yet an unsolved proposition, although various theories have been 
advanced in explanation of the process. 

Pathology and Morbid Anatomy. — Gouty deposits are met with only 
in tissues which have a scanty vascular supply, or in which the circulation 
is more or less sluggish. Tophi are most frequently found in the tissues 
which surround the joints, like the cartilages, aponeuroses, and perios- 
teum. The small joints are most often affected. The relation of the teeth 
with the alveolar process is that of gomphosis, a species of joint termed 
the dento-alveolar articulation, and the tissue which intervenes between 
the cementum and the bone is the pericementum, a dense fibrous structure 
having a scanty vascular supply as compared with the somewhat analogous 
structure, the periosteum. Under certain conditions exostosis and nodular 
formations occur upon the surfaces of the bones as a result of the irritation 
of the periosteum from the presence of the gouty poison in the blood and 
its deposition within the tissues. The same condition has already been re- 
ferred to as occurring upon the roots of the teeth from the same cause. 
There would seem to be, therefore, no good reason for objecting to the con- 
clusion which has been reached by so many able observers, — viz., that the 
deposits formed upon the roots of the teeth primarily in the pericementum 
and in closed pockets which could not have been at any time in commu- 
nication with the oral cavity, must have been deposited from the blood ; 
and, inasmuch as tophi are also found in the periosteum surrounding a 
joint, the inference is fair that similar tophi may be formed in the peri- 



HEMATOGENIC CALCIC PERICEMENTITIS. 559 

cementum surrounding the root of the tooth and forming the " joint" with 
the alveolar process. 

Formation of Deposits. — In relation to the manner or modus operandi 
of the formation of these tophi, Mordhorst * says, ' ' The granular urate is 
always the precursor of the crystalline form, and in the body-fluids the 
uric acid circulates in the form of invisible granules of sodium urate. 
Gouty deposits are only met with in non- vascular tissues, and as acids 
and acid salts diffuse more rapidly and readily than alkalies and alkaline 
salts, we must suppose that the alkalinity of the non-vascular tissues is 
less than that of the blood. Hence if a transudate almost saturated with 
urate enters such a less alkaline tissue the solution becomes supersaturated 
and granular urate is precipitated in the tissue, the precipitation being 
favored by such additional factors as lowered temperature or increased 
concentration of the fluids of the tissue. The precipitation of the granular 
urate in the spaces of the interstitial tissue and in the lymph -channels is 
the cause of the various phenomena of gout. In the course of time the 
urate deposited becomes converted into acicular crystals of sodium biurate, 
or under favorable conditions may be redissolved and disappear, and with 
them disappear the lesions to which they gave rise." If this theory is 
correct it explains why constitutional treatment, which aims to redissolve 
and eliminate the biurates, often mitigates the severity and sometimes 
cures certain cases of gouty pericementitis. 

Ebstein f believed that in gout uric acid is formed in excess in the body, 
and that hyper-production also takes place in regions which ordinarily 
do not produce uric acid, as, for example, the bone-marrow, the carti- 
lages, etc. 

When the blood and the lymph are overcharged with uric acid it may 
act as a chemic poison, causing morbid processes in the tissues and 
giving rise even to necrobiotic changes ; when these have reached a cer- 
tain degree the biurate is deposited in the necrotic parts of the structures, 
whereas such deposition is never found elsewhere. 

Klemperer J is of the opinion that "the phenomena of gout cannot be 
explained by a mere crystallization of urates from the blood, or by the 
production of necrotic changes due to its presence in the circulation, 
seeing that in other conditions in which uric acid is present in excess in 
the blood, such as leucocythsemia and chronic nephritis, neither uratic 
deposits nor necrosis of cartilage are met with. Some unknown sub- 
stances produce in gouty j>ersons inflammation and necrotic changes in 
various tissues, and the necrosed tissues possess the power of attracting 
to themselves the excess of uric acid in the blood, while the chemic 
affinity of the necrosed parts for uric acid prevents the deposits from being 
redissolved by the blood. 

The writer has called attention to the fact § that rheumatic aud gouty 

* Zeits. f. klin. Med., p. 65, 1897, from Sarjou. 
f Nature u. Behandlung d. Greht., from Sarjou. 
t Deutsche med. Woch., xxi. p. 655, 1895-, from Sarjou. 

§ The Rheumatic and Gouty Diathesis, as manifested in the Peridental Membrane, 
Journal of the American Medical Association, 1891. 



560 OPERATIVE DENTISTRY. 

conditions are often observed in the form of inflammation of the peridental 
membrane as a primary symptom of an approaching acute attack of 
articular rheumatism or of gout, and that many times this condition is 
the only local expression of the diathesis. This fact has been overlooked 
by the general practitioner, and consequently no mention is made of this 
symptom of gout and rheumatism in works upon these diseases. 

The fact of the acute susceptibility of the peridental membrane to the 
presence of the materies morM of these diseases is a clinical fact which has 
only been recognized by dental specialists during the last few years. In- 
flammation of the pericementum as a manifestation of the gouty diathesis 
is proved by the relief obtained from the exhibition of therapeutic reme- 
dies which eliminate the uric acid from the system. 

In the preceding pages it has been shown upon the best authority that 
gout, which is primarily a joint affection, may also exist in certain dis- 
orders of the blood-vessels, the circulation, the blood, the secretions, the 
muscles, the kidneys, the liver, the stomach, the nervous system, the skin, 
,the periosteum, the bones, the hair, the nails, etc. The effects upon these 
tissues and organs of the presence in the system of an excess of uric acid 
are peculiar to each particular kind of tissue and to the function of the 
organ, the variety of the manifestations being as numerous as the tissues and 
organs affected. 

In the periosteum, the character of whose tissue most nearly approaches 
that of the pericementum, these manifestations are, as already noticed, of 
two forms, one chronic in character, which results in the formation of nodes 
and exostoses, and the other acute, in which uratic deposits are present. 

These deposits may be in the form of defined concretions, when they are 
readily detected ; but, as pointed out by Mordhorst, they may be deposited 
in the form of invisible granules and later converted into acicular crystals 
of sodium urate, which still might be so small as to escape detection. 

The deposits which are formed upon the roots of the teeth in gouty 
pericementitis are thin, greenish- colored, hard scales composed of urates 
of sodium, calcium, etc., which are very adherent and often require con- 
siderable force to dislodge them. These concretions may be located upon 
any aspect of the root, but most frequently upon the lingual and approxi- 
mal surfaces towards the apex. 

Uratic deposits upon the roots of the teeth are, however, not so common 
as might be supposed from the literature upon the subject. All calcic de- 
posits of dark color found upon the roots of the teeth are by no means evi- 
dence of a gouty condition of the system. Such deposits which have been 
exposed to the fluids of the mouth and constantly bathed with pus will 
always be dark colored and have the appearance of being formed from 
tiny globular masses, a condition usually observed in the concretions 
which have accumulated upon the surfaces of foreign bodies, bullets, frag- 
ments of metal, etc., which have been buried in the tissues and bathed in 
pus for a considerable period. This same form of deposit is found upon 
the roots of devitalized teeth which penetrate the floor of the antrum of 
Highmore, and which, by inducing septic infection of this sinus through 
the agency of a putrefying pulp, has caused empyema. 



HEMATOGENIC CALCIC PERICEMENTITIS. 561 

Roots of teeth which have been forced into the antrum in an effort to 
extract thein, teeth which have erupted into this sinus, and foreign bodies 
which have been introduced by traumatism invariably induce suppuration. 
These bodies after a time become covered with concretions which have a 
dark-green color and a roughened surface like that just described. 

The variety of deposit found upon foreign bodies and the roots of teeth 
seems to be peculiarly and almost invariably the result of the suppurative 
process, the concretion being calcic material, and rarely responding to the 
murexide test for uric acid. 

Concretions which are identically the same are frequently found upon 
the ' ' roots of the teeth in pyorrhoea alveolaris in its later stages, when the 
roots of the teeth have been bathed in pus and the oral secretions for 
months, and the deposit constantly accumulating until the tooth is ex- 
foliated. Cases of this character when tested for uric acid usually give 
negative results, and yet it is largely this class of cases which have been 
selected for chemical analysis with the view of discrediting the theory 
that uric acid plays an important part in producing that peculiar form of 
pericementitis accompanied with suppuration which has been designated 
"gouty pericementitis." 

The deposits in true gouty pericementitis are formed in tiny islands of 
irregular outline, and in the form of thin scales with smooth surface, dark- 
green in color, and very firmly adherent to the surface of the cementum. 
These deposits are doubtless formed in the pericementum through the 
agency of some unknown substances, as suggested by Klemperer, which in 
gouty persons produce inflammation and necrobiotic changes, while the 
necrosed tissues possess the power of attracting to themselves the excess 
of uric acid in the blood. The chemic affinity of the necrosed tissues for 
uric acid also prevents them from being redissolved by the blood when it 
has assumed its normal alkalinity. 

The presence of these deposits upon the root of the tooth produces 
symptoms of irritation of the pericemental membrane. Sooner or later 
this develops inflammation and the formation of an abscess at the location 
occupied by the deposit, which may point directly through the gum or 
burrow along the side of the root and discharge at the cervix. These 
abscess pockets, as the writer pointed out some years ago, have no com- 
munication with the oral secretions until pointing takes place, and this 
fact has been demonstrated over and over again by the most thorough and 
painstaking examinations. The infection, therefore, which induced the 
suppurative process could not have occurred from the mouth, — unless the 
suggestion of Black* is correct, that "infection may possibly take place 
through the glandular structures which he has discovered in the pericemen- 
tum," — but most likely it has come through the avenue of the circulation. 
For this reason the writer is of the opinion that the gouty deposits in the 
pericemental membrane do not immediately cause suppuration, and that 
the presence of the pyogenic cocci in the blood-current are necessary to 
establish this process. 

* Dental Review, vol. xi. p. 258. 
36 



562 OPERATILE DENTISTRY. 

The character of the inflammation which is primarily established in 
these cases is always acute, the abscess usually pointing in from twenty- 
four to forty-eight hours. The presence of the concretion is readily demon- 
strated by laying the abscess open, excavating the pus, and packing the 
cavity with a tiny strip of gauze or a pledget of cotton for a few hours or 
overnight. On removing the dressing and irrigating the cavity the deposit 
is brought to view. This would seem to settle the question of the deposit 
being the cause of the irritation, and that it was not formed as a result of the 
suppurative process, as this is acute and of such brief duration that a con- 
cretion of this character could not be formed in so short a time. Neither 
is it possible for the concretion to have been deposited from the oral secre- 
tions, for no communication existed between them until the abscess pointed. 

Symptoms and Diagnosis. — The first symptom of gouty perice- 
mentitis is soreness and elongation of the tooth, followed in a few hours in 
the suppurative variety by swelling of the gum either upon the buccal or 
lingual aspect at locations varying from midway of the length of the root 
to the apical region. The swelling is accompanied by considerable pain 
of a throbbing character. At the end of twenty-four to forty-eight hours 
fluctuation may be felt, and upon opening the swelling pus escapes. The 
early stages of the disease so closely simulate septic apical pericementitis 
and dento-alveolar abscess that it may readily be mistaken for these affec- 
tions. It may, however, be differentiated from them (1) by the fact that 
the teeth affected are usually vital ; (2) that the swelling is generally con- 
fined to the gum over the affected tooth, and rarely extends to the overlying 
soft tissues ; (3) the character of the pain is not so severe nor the duration 
of the attack so prolonged ; (4) the abscess is limited to a comparatively 
small area, and there is usually no communication between the abscess- 
cavity and the apical space. The peculiarity of this variety of abscess is 
that it is formed about a tophus located upon the surface of the cementum, 
and that until the abscess ruptures there is no communication between it 
and the cavity of the mouth. 

Prognosis. — The prognosis will depend largely upon the success of the 
constitutional treatment in eliminating the uric acid from the system and 
preventing its excessive formation afterwards, and also in the thorough- 
ness with which the irritating concretions are removed from the roots of 
the teeth. Marked and almost immediate relief is frequently obtained by 
vigorous general therapeutic measures addressed to the elimination of the 
quadrurates. A favorable prognosis cannot be hoped for, however, by 
constitutional treatment alone. Local treatment must be instituted for the 
removal of the concretions, and this must be effectually done if the sup- 
purative process is to be controlled. 

Because one or more teeth have been attacked by this disease it does 
not follow that all of the teeth, or even any others, will be so affected. 
The disease usually manifests itself in those teeth which have suffered in- 
jury of some form to the pericementum whereby its resistive power has 
been weakened. Constitutional measures which have for their object the 
control of the disease by restricted diet and proper exercise must be 
rigidly carried out if the desired object is to be gained. Half-way meas- 



HEMATOGENIC CALCIC PERICEMENTITIS. 



563 



ures are worse than useless. The prognosis will be unfavorable if the irri- 
tating concretions are not removed or the constitutional dyscrasia com- 
bated. Such cases are marked by chronic inflammation and suppuration, 
loosening and extrusion of the tooth, which may also turn upon its axis 



Fig. 633. 



Fig. 634. 





After Dr. George S. Allan. 



After Dr. George S. Allan. 



and form a wide separation from its neighbor on one side. Dr. George S. 
Allan presented to the New Jersey State Dental Society casts taken 
from the mouth of a gentlemen which represent these features of the 
disease. Fig. 633 represents the denture before the disease appeared ; 

Fig. 635. 




After -Dr. George S. Allan. 

Fig. 634 shows the condition one year later ; Fig. 635 exhibits the case 
with the tooth permanently elongated after treatment, while Fig. 636 shows 
the appearance of the denture after the tooth had beeu shortened by grind- 
ing to match its fellow. 

Fig. 636. 




.V..- r 



After Dr. George S. Allan. 

Treatment. — The treatment of gouty pericementitis to be effective 
must be applied to both the local and the constitutional conditions. 

Local Treatment. — The treatment of the local conditions compre- 
hends the removal of the deposits, the control and suppression of the in- 
flammatory symptoms, the stimulation of the healing process, the institu- 
tion of thorough and vigilant oral hygienic measures, and the support of 




564 OPERATIVE DENTISTRY. 

the teeth, to obtain surgical rest, as already described under the head of 
ptyalogenic calcic pericementitis. 

The tophus may be readily discovered by opening the abscess by means 
of a curved incision, lifting the flap, and packing the cavity for a few hours 
with gauze or cotton. 

After removing the concretion the cavity should be irrigated with an 
antiseptic solution, the flap brought into apposition and retained until 
healed by a couple of sterilized horse-hair sutures. 
(Fig. 637). 

Constitutional Treatment. — The constitutional 
treatment of gouty pericementitis is that which should 
be prescribed for gout in general. Any regime which 
will prevent the accumulation of an excess of uric 
acid in the blood or effect its elimination when formed 
will produce beneficial results in gouty pericementitis. 
Preventive Treatment. — Prophylactic treatment 
Gum turned aside, show- in gouty conditions of the system should be instituted 
ing underlying condition m rf enough in those individuals who have inherited 

a case of pyorrhoea alveo- J & 

laris. a, cervix of tooth ; the predisposition to ward off a first attack ; or after 
b, thickened and degener- the development of the disease to prevent or, at least, 

ated pericementum ; C, al- ' 

veoiar process thinned .and to retard the recurrence of any future attack. This 
irregularly absorbed ; d, ma y ^ e accomplished by a restricted diet and by proper 

flaps of gum. * . A ■ 

amount of out- door exercise. 

Gouty individuals and those with the inherited tendency to the affec- 
tion should eschew all food which contains much nuclein, as this substance 
tends to increase the percentage of uric acid in the blood. Sweetbreads, 
liver, brains, kidneys, and meat extracts all contain large quantities of 
nuclein, hence are contraindicated in gouty subjects. Eggs are admissi- 
ble, as they contain no nuclein, but instead paranuclein, which during the 
metabolism of digestion and assimilation is not converted into uric acid. 
Meat and fish contain proteids, but as this substance is not decomposed to 
form uric acid, a moderate amount of these foods may be taken. Sarjou 
places the daily allowance at two hundred grammes, a trifle over seven 
ounces. A larger quantity he thinks would overtax digestion and the 
eliminative powers of the kidneys. 

Haig* says, "The uric acid taken in the food constitutes the bulk of 
the uric acid eliminated. The avoidance of animal food containing xan-v 
thin compounds or uric acid, and also tea, coffee, and cocoa, whose alka- 
loids are similar xanthin compounds, will gradually eliminate any excess 
of uric acid in the system." 

Kolisch f would eliminate every influence which might tend to irritate 
or injure the kidneys, and he regards alcohol and foods which might in- 
crease the amount of the irritating alloxins as especially harmful in this 
direction. Among the latter he classes flesh rich in cellular elements, 
while muscle, particularly if it has been boiled, he regards as permissible. 

* British Medical Journal, March, 1897. 
t Wiener klin. Woch., No. 45, 1895. 



HEMATOGENIC CALCIC PERICEMENTITIS. 565 

Milk and eggs he thinks are free from objection, as the nucleins (para- 
nuclein) which they contain do not form alloxins. The carbohydrates and 
fats he thinks are allowable, and vegetables, — salads and greens, — except- 
ing asparagus, are useful. 

Nothnagel* recommends as a diet for gouty patients plenty of fresh 
vegetables, fruits, and starchy food, small quantities of meat, and the 
exclusion of sugars. 

Laquerf recommends fatty milk, according to Gartner's formula, as a 
suitable diet for all cases of gout. He thinks the administration of milk 
increases the excretion of xanthin bases and reduces that of uric acid. An 
increased quantity of water in the diet increases the alloxin bodies (uric 
acid and xanthin bases) in healthy persons. 

Wood | thinks that milk probably suits the largest number of gouty 
patients, but believes there is no diet for gout. The diet must be adapted 
to the individual case. Nevertheless, in a large majority of cases, sugar 
and starches must be cut off. But in spare gouty subjects a farninaceous 
diet may be essential. 

The ingestion of large quantities, three to four pints or more, of fluids, 
such as milk and pure water, especially skim-milk and buttermilk, and dis- 
tilled water or lithia water, is to be recommended, to favor the free action 
of the kidneys and to stimulate the elimination of the waste products. 

Alkaline waters were at one time very widely recommended in gout 
and rheumatism, but experience has shown that when the waters contain 
soda in any appreciable amount their ingestion is liable to accelerate the 
deposition of the biurate and thus provoke an attack of gout. (Sarjou.) 

Alcohol as a beverage in whatever form should be eschewed by gouty 
subjects, as numerous observations have proved its pernicious effects. 
Alcohol increases the formation of uric acid and favors the deposition of 
the urates. The pernicious effect of alcoholic beverages in these cases is 
thought to be due to the incomplete process of fermentation by which they 
are produced. 

The light wines are the least injurious, and Bordeaux, Mosel, and Bhein 
wines may be taken in small quantities ; but the stronger wines, like 
sherry, port, and champagne, and ale, porter, and stout, should never form 
a part of the diet of a gouty individual. In certain persons a glass of any 
of these beverages would be sufficient to provoke an attack of acute gout 
of the great toe, a gouty sick headache, or an attack of pyorrhoea alveolaris. 

Exercise. — Exercise to be beneficial as a prophylactic measure in 
gouty conditions should be regular, and of such a vigorous nature as to 
bring a healthy glow to the surface of the body and stimulate the emunc- 
tory organs. Such exercise should be taken out of doors, and may consist 
of walking, riding, cycling, or playing tennis, golf, cricket, base-ball, etc. 
1 ' Over-exercise is harmful on account of the tendency to increase the 
alloxin productions." (Kloisch. ) 



* Internat. klin. Rundschau, February 14, 1892. 
t Berliner klin. Woch. , September 7, 1896. 
t New York Medical Eecord, July 10, 1897. 



566 OPERATIVE DENTISTRY. 

Treatment of Acute Attacks. — In the systemic treatment of acute 
attacks of gout, it is obvious that the treatment should be directed towards 
the elimination of the excess of uric acid and its compounds which are 
present in the blood and tissues of the body. 

Until quite recently alkalies and alkaline combinations have been the 
most generally favored remedies in the treatment of gouty conditions. Of 
these combinations the most generally employed were the carbonates and 
phosphates of sodium and potassium and the carbonate of lithium. The 
use of these remedies was based upon the supposition of an acid condition, 
or rather a lessened alkalinity of the blood, and that by the ingestion of 
alkaline remedies the alkalinity of the blood would be increased and its 
power to dissolve uric acid and prevent the deposition of the biurate 
greatly augmented. The experiments of Roberts have proved these sup- 
positions to have been based upon false premises. In the first place, there 
is no such thing as an abnormal acidity of the blood in gout, and, second, 
" the addition of the carbonates and phosphates of alkalines to blood-serum 
impregnated with uric acid did not retard the precipitation of biurate ; 
the alkalines are consequently without power to prevent the formation of 
uratic deposits, and the salts of soda may even prove directly pernicious 
when taken in large doses." (Levison.) 

The alkaline lithiu mcompounds — the citrate and carbonate — have been 
quite extensively employed in the milder cases of gout, the subacute and 
chronic forms, and with seeming good results. Tartarlithine, lithium 
bitartrate, and alkalithia, prepared in five-grain tablets, are very conve- 
nient for use. They may be prescribed, one tablet dissolved in a glass of 
hot water three or four times per diem. 

Of the mineral springs the Saratoga, Vichy, Buffalo lithia, Carlsbad, 
and Apollinaris are probably the best. Among the prepared waters the 
ozonated lithia is the best. Waters of this character to be of real benefit 
should be drunk in large quantities, so as to increase the excretion of urine 
to from three to five pints daily. 

Among the other remedies which are employed to eliminate the waste 
products and check the excessive formation of uric acid are colchicum, 
guaiacum, calomel, and the salicylate of sodium. 

In order to check the excessive production of uric acid it is necessary 
to promote liver-metabolism and relieve the congested state of the portal 
system. These results may be secured by regulating the diet and daily 
regimen and the administration of colchicum. This drug is usually ad- 
ministered as wine of colchicum, in doses of twenty-five minims three 
times per diem. Or it may be combined with three to five minims of the 
tincture of aconite. Colchicum must be used with circumspection, as it is 
liable, if administered in large doses, or its use long continued, to produce 
nausea and diarrhoea. For these reasons ihe use of the drug should not be 
continued in any case for more than four to six days. Colchicum not only 
relieves the torpid condition of the liver and the portal system, but it 
relieves the severe pain of gout better than any other drug. Its mode of 
action, however, is obscure. 

Guaiacum also stimulates hepatic metabolism and checks excessive uric 



HEMATOGENIC CALCIC PERICEMENTITIS. 567 

acid formation. It also stimulates the kidneys, and assists them to elimi- 
nate the uric acid formed in them, and prevents its absorption by the blood. 
This drug is usually prescribed in the form of the tincture guaiaci ; dose, 
one to two fluid rachms three times per diem, administered preferably in 
milk. 

Calomel is administered for the same purpose, but the best results are 
obtained by giving it in divided doses until it freely moves the bowels. 

"To promote the elimination of the quadrurates formed in the kidneys 
and so to prevent their absorption into the blood is to strike at the primary 
evil in the causation of gout. To promote this, diuresis should be increased 
and the acidity of the urine diminished. Citrate of potassium is a good 
diuretic, which not only increases the solubility of the quadrurates, but 
also diminishes the acidity of the urine, and should be continued until 
moderate alkalinity of the urine is produced." (Luff.) 

Salicylate of sodium and the salicylate of lithium have been more or 
less extensively employed in the treatment of acute gout, but they are 
greatly inferior to colchicum. 

These remedies find their most useful field in those cases in which 
colchicum is not well borne by the stomach. They have the power of 
clearing the system of uric acid, but they do not reach the primary cause 
of the disease, which lies in a faulty metabolism. 

Various basic organic compounds, such as piperazin, lycetol, and 
lysidin, have been recently introduced as specifics for gout and uric acid 
gravel. But the opinions as to their value are so conflicting that they can- 
not at present be recommended. 

In this study of gouty pericementitis the writer has endeavored to 
present the subject in such a manner that the student may get a somewhat 
broad view of that condition of the general system known as "uricaci- 
dsemia," and its manifestations in the various tissues of the body other 
than those which surround the root of the tooth, with the hope that the 
presentation will assist in clearing up some of the misconceptions of those 
who oppose the theory and of some of its over-zealous advocates who 
have claimed too much for it. 



CHAPTEE XL. 

PHAGEDENIC PERICEMENTITIS. 

Definition. — Phagedena (from the Greek tpayeiv, to eat) is a spreading 
and destructive ulceration, often of an obstinate character, which rapidly 
destroys or disintegrates the soft parts. 

Dr. Black first introduced the use of the term ' l phagedenic pericemen- 
titis" to describe a peculiar form of pyorrhoea alveolaris whose most char- 
acteristic symptom was a progressive ulceration and destruction of the 
pericementum and alveolar process. 

Phagedenic pericementitis may be described as an inflammation of the 
peridental membrane accompanied with a progressive ulceration of a 
phagedenic or spreading type, showing a marked inclination to extend or 
progress most rapidly in a direction corresponding to the long axis of the 
tooth, and beginning apparently at the gingival border of the gum in a 
slight gingivitis, but really in the marginal attachment of the membrane. 
The disease causes destruction of the pericemental membrane and of the 
alveolar process immediately overlying the inflamed area, but in the early 
stages leaves the gum intact. This process of disintegration is accom- 
panied with a slight reddening and congestion of the overlying gum, the 
formation of deep narrow pockets, the deposition in some cases of calcic 
material, and the discharge of a variable quantity of pus which makes 
its appearance on pressure being applied over the inflamed area. 

The disease may be either acute or chronic in its manifestations. 

Phagedenic pericementitis is entirely distinct from hematogenic calcic 
pericementitis, in that the inflammation is not dependent upon the forma- 
tion of uratic deposits, and that the destructive process always begins at 
the marginal attachment of the membrane and progresses towards the 
apex of the root, spreading less rapidly in lateral directions, and destroy- 
ing the pericementum and alveolar tissue simultaneously by a process of 
molecular necrosis, while it presents clinic features which indicate it to be 
an infectious disease. In hematogenic calcic pericementitis the inflamma- 
tory process is dependent upon the formation of uratic deposits within the 
peridental membrane ; these concretions are deposited in locations remote 
from the marginal border of the membrane ; they form distinct abscesses, 
which are confined at first to these locations, and have no connection with 
the oral cavity until the abscess ruptures ; neither does the affection show 
any characteristics of an infectious disease. In other respects they have 
many features in common. 

Causes.— In regard to the nature and etiology of phagedenic perice- 
mentitis very little is positively known. Certain general and local con- 
ditions seem, however, to have a bearing upon the disease, either as causa- 
tive or resultant factors. It is true that some of these conditions seem to 
act as predisposing and others as exciting causes of the affection. They 



PHAGEDENIC PERICEMENTITIS. 569 

may therefore be divided into predisposing and exciting causes, the former 
being largely of constitutional origin, the latter principally local. 

Predisposing Causes. — Certain systemic conditions, by a seeming 
predilection, find expression in various inflammatory manifestations in the 
peridental membrane, some of which are constructive in their character, 
others destructive ; as, for instance, certain gouty conditions cause through 
irritation of the pericementum and stimulation of the cementoblasts the 
formation of new cement-tissue (hypercementosis), or in scurvy, which 
causes through intense inflammation of the pericementum destruction of 
this membrane and exfoliation of the teeth. 

Phagedenic pericementitis generally arises under the influence of cer- 
tain diseases or unfavorable conditions of health, — conditions which are 
productive of general debility and degenerations of special tissues like the 
pericementum, — and it is manifested either as a complication or as a 
sequel of these conditions and diseases. Among the more common general 
conditions and diseases which are sometimes complicated with phagedenic 
pericementitis or are followed by it are hereditary tendencies, anaemia, 
locomotor ataxia, diabetes mellitus, albuminuria, osteitis deformans, scurvy, 
certain nervous diseases, typhoid fever, tropical fever, certain infectious 
diseases, particularly the exanthematic fevers, influenzal, smallpox, syph- 
ilis, gonorrhoea, and tuberculosis, pyaemia, nephritis, pregnancy, sterility, 
and the selective action of those drugs which produce mercurial isru, pluin- 
bism, iodism, and alcoholism. 

The pericementitis of scurvy, mercurialism, plumbism, and iodism in 
their aggravated forms are always of the phagedenic type. 

It should be remembered, however, that the teeth are dermal append- 
ages, and are therefore more liable on this account to be affected by such 
diseases and drug impressions as are peculiarly manifested in or have a 
predilection for epiblastic and hypoblastic tissues. The teeth are also in 
a certain sense transitory organs, and afe therefore prone to take on senile 
and other degenerative changes, resulting in atrophy of the pericementum 
and alveolar structures and loss of the teeth. For this reason some 
authorities have looked upon phagedenic pericementitis as a "premature 
senile degeneration" or alveolar atrophy. The disease is most common 
between thirty and fifty years of age. 

It is interesting to notice the great similarity in the clinic features of 
phagedenic pericementitis and of the oral manifestations of osteitis de- 
formans as described by Sir James Paget. He says, "The surrounding 
gum becomes spongy, deep red, and sometimes tender ; it separates from 
the neck of the tooth, while at the same time the periosteum (perice- 
mentum) suppurates and discharges pus, which is continually oozing out 
around the necks of the teeth, and can be generally pressed out in great 
quantity. It is extremely chronic, beginning generally in early middle 
age and may continue for an indefinite time without influencing the gen- 
eral health. The early stages of the disease are sometimes attended with 
pain varying widely in severity. The breath is usually foul, the roots of 
the teeth covered with irregular masses of greenish or blackish tartar, the 
discharges offensive, and the whole mouth tender." 



570 



OPERATIVE DENTISTRY. 



Certain local conditions, like traumatisms, malocclusions, loss of antag- 
onizing teeth, unhygienic conditions of the mouth, disease of the teeth, 
marginal gingivitis, etc., act as local predisposing causes of the disease. 

Exciting Causes. — According to Black, the disease may have " its 
beginning in a gingivitis that in its inception cannot be distinguished from 
the simple form, or its character may be marked by deposits of either 
salivary or serumal calculus." 

The active or exciting causes of the disease, in the opinion of the writer, 
are local traumatisms and pyogenic infections which induce a marginal 
gingivitis ; this, through the continuity of structure, is transmitted to the 
already debilitated pericementum, when the conditions are favorable, 
through a lowered vital resistance, for the development of the pus-pro- 
ducing micro-organisms. 

Traumatic injuries of the margins of the gums, caused by the sharp par- 
ticles of very hard foods or the lodgement of such particles beneath the free 
margins of the gams, the too vigorous use of the toothbrush, toothpicks, and 
floss-silk, or the accumulation of cervical deposits, are frequent ; such wounds 
and abrasions, though slight, may nevertheless readily establish infection 
by giving entrance to the tissues of the pyogenic organisms of the mouth. 
And as debilitated tissues are prone to degenerative changes, inflammation 
and ulceration are readily produced. Or a marginal gingivitis may be 
established through a catarrhal condition of the oral mucous membrane 
following a general catarrhal state of the upper air-passages, induced by 
coryza or influenza, or it may be produced by unhygienic conditions of 
the mouth, the result of improper care, or by thermic irritation of the 
mucous membrane, induced by the ingestion of excessively hot liquids 
and foods. 

Pathology. — An examination of the teeth which have been lost by 
phagedenic pericementitis may not discover any abnorjnal appearances, 
except that the roots are denuded of every vestige of the peridental mem- 
brane. They may have deposits upon their roots or they may be entirely 
free from them. The teeth are usually of fine organization and dense 
structure, and singularly free from caries. The pulp-chamber is usually 
small, and the pulp shows evidences of atrophy. 

An examination of the teeth in situ reveals the fact that upon one side 
the root is denuded of its pericementum to a considerable depth, while 
perhaps upon all other sides it is intact. This denudation of the peri- 
cementum is most often upon the lingual or buccal aspects of the root in 
the order named, while it is less rarely found upon the mesial and distal 
surfaces. The alveolar process is usually destroyed to nearly the same 
depth as the pericementum, while the edge is denuded and rough and 
apparently the seat of caries, if one may judge from the peculiar odor of 
the pus (characteristic of bone caries) which exudes from about the mar- 
gins of the gums. This degenerative process sometimes destroys the 
pericementum and the alveolar septum between two approximating teeth, 
while the remaining parts are unharmed for a considerable period there- 
after. The pockets not infrequently extend to the apex and involve the 
apical space, even permitting an instrument to pass over the apex, while 



PHAGEDENIC PERICEMENTITIS. 571 

the attachment of the membrane to the balance of the alveolus will remain 
in a comparatively normal condition for an indefinite period. The formation 
of a pocket upon one side of the root usually causes the tooth to move 
out of position, the displacement occurring in a direction from the dis- 
eased surface. (Black.) Occasionally the entire gingival margin of the 
pericementum is attacked and the whole membrane rapidly destroyed, 
causing extrusion of the tooth and finally exfoliation. 

The examination develops the further fact that some of these cases have 
subgingival deposits upon their roots, while others do not. The formation 
of the deposits in these cases is evidently the result of the disease, and 
the calcic material is in all probability derived from the salivary secre- 
tions and the pus. Gingivitis is the rule wherever calcic deposits are 
found upon the roots of the teeth. Black thinks in these cases the phage- 
denic pericementitis is complicated with " calcic inflammation," and that 
1 ' this dual condition has long delayed the recognition of phagedenic peri- 
cementitis as an independent disease.' 7 

In those cases which do not present calcic deposits there is often an 
absence of gingival inflammation, and instead there is an atrophic con- 
dition of that portion of the gum-tissue which has lost the support of the 
alveolar process, which often exposes the root to the extent of the lost 
alveolar plate. 

The gums, as a rule, give little or no evidence by their appearance of 
the condition of the pericementum and alveolar plate lying beneath. Oc- 
casionally, however, the ulcerative process which has attacked the peri- 
cementum will be communicated to the gum and the tissue overlying the 
pocket rapidly destroyed. The edges of the notch thus formed in the 
gum-tissue will be covered with very red, coarse granulations, which bleed 
upon the least provocation, and are covered in the morning with an ichorous 
discharge. After the ulcerative process reaches the limit of the destroyed 
alveolar plate the edges of the gum heal and form a close union with the 
exposed surface of the root, thus obliterating the pocket, and in many 
instances controlling, and in a few others completely arresting, the further 
progress of the affection. This, the writer believes, is nature's method 
of curing the disease. 

Another peculiar feature of this disease, which was first pointed out by 
Black, is a thickening and eversion of the alveolar margins. The phe- 
nomenon is peculiar in that as the alveolar plate is thinned 'upon the sur- 
face lying next to the root of the tooth new bony material is laid down 
upon its gingival surface, so that upon examination the alveolar edge is 
found to be not only thickened but has the appearance of being everted. 

The disease is irregular in its attacks ; sometimes it will be confined for 
a considerable period to the side of the root of a single tooth, or of two or 
more teeth upon the same side of the mouth ; at others it may attack one 
or more teeth upon opposite sides of the mouth,— and this is the more com- 
mon condition, — and then spread to adjoining teeth until one by one the 
entire denture may be lost. This latter peculiarity of the disease has 
given rise to the opinion among some authorities that it was infectious in 
its nature. , Neither individual teeth nor groups of teeth seem to possess 



572 OPERATIVE DENTISTRY. 

any especial liability to be attacked by the disease, but all are equally 
susceptible. 

Witzel, Black, Arkovy, Izlai, Miller, and others are of the opinion 
that the disease is essentially infectious, and that it has its origin in some 
specific micro-organism ; but none of these investigators has as yet been 
able to isolate the specific germ. On the other hand, the fact that the dis- 
ease shows a marked tendency to bilateral symmetry, and the teeth first 
attacked are often not those which are most liable to ptyalogenic deposits, 
strengthens the theory of its constitutional origin. 

Symptoms and Diagnosis. — The most marked and characteristic 
symptoms of phagedenic pericementitis are a thickened and turgid condi- 
tion of the margins of the gums, the ulceration and destruction of the 
peridental membrane upon one or more sides of the root, forming deep 
pockets, which may reach to the apex, or the destruction of the perice- 
mentum may progress until it encircles the entire root. The process of 
ulceration always begins at the cervical margin, and progresses most rapidly 
in a direction towards the apex. Accompanying the ulcerative process 
there is a discharge of pus and a molecular disintegration (caries) of the 
alveolar process. The odor of the pus is characteristic of caries of bone. 
The edges of the alveolar process are denuded and rough, and the disinte- 
gration of this tissue keeps pace with the destruction of the pericementum. 

Loosening of the teeth is an early symptom, the degree depending upon 
the character of the inflammation and the extent of pericemental and 
alveolar destruction. 

The gum in the early stages of the disease, as a rule, maintains its in- 
tegrity over those portions of the root which have lost the pericementum 
and alveolar plate, but in the more advanced stages recession takes place, 
sometimes by atrophy, at others by ulceration. 

When the gum is being destroyed by ulceration the margins are cov- 
ered with coarse granulations of an indolent character, and are covered 
during the intervals between meals, and in the morning, with an ichorous 
discharge. The discharge of pus is most abundant in those cases in which 
the pockets are deep and the gum intact. 

An atrophy or ulceration of the gum which progresses to the limit of 
the loss of the pericementum and alveolar plate obliterates the pocket and 
tends to an abatement of the symptoms of the disease. 

As a rule, little or no pain attends the progress of this form of pyor- 
rhoea alveolaris. 

A marked symptom of the disease is the movement or displacement of 
the teeth, Avhich begins as soon as a pocket is formed at the side of the 
root. This movement takes place in a direction opposite to the surface 
upon which the pocket is formed, as, for instance, in a superior central 
incisor, if the pocket is upon the lingual surface, the tooth moves out- 
ward, if upon the mesial surface, it moves distally, etc. In other cases 
the tooth will turn upon its axis, usually in an outward direction, causing 
the mesio-labial angle to become most prominent when the pocket is upon 
the mesial surface, etc. 

Deposits are rarely found upon the roots of the teeth in the early stages 



r 



Fig. 638.— Fibroid degeneration of the pulp fr 



(V. A. Latham.) ■' 110. 







-Human pulp in situ showing calcic degeneration. (V. A. Latham.) X 65. Thrombus in 
vessels at A and calcific areas at B. 






* -*'» „ ** 







Fig. 640.— Hyaline defeneration of the pulp. (V. A. Latham.) X 100. 




Fig. 641.— Colloid degeneration of the pulp. (V. A. Latham.) X 21.! 



PHAGEDENIC PERICEMENTITIS. 573 

of the disease, except at the cervices, but in the later stages of the chronic 
form the presence of dark-green deposits is the rule. In fact, the presence 
of deposits marks the chronic form of the disease. In the acute form de- 
posits are rarely or never formed upon the roots. 

These facts seem to prove very conclusively that calcic deposits are not 
the cause of this form of the disease, but are rather a consequence of it, 
being formed from the salivary secretions and the pus. 

Death of the pulp sometimes occurs as a result of the involvement of 
the apical tissues in the process of pericemental ulceration, or it may 
occur as a result of degenerative changes. These degenerations may be 
fibroid in character, as shown in Fig. 638, or calcic, as seen in Fig. 639, or 
hyaline, as represented in Fig. 640, or colloid, as shown in Fig. 641. Under 
such circumstances the disease may be complicated with an alveolar ab- 
scess. In multiple-rooted teeth one root may be so affected while the pulp 
in the others may still be vital. 

As the disease progresses the teeth become more and more loose, until 
finally they are picked out with the fingers or they drop out. 

Differential Diagnosis. — There are two disorders affecting the peri- 
cementum and the alveolus which under certain circumstances might be 
mistaken for this disease, — viz., gouty pericementitis and alveolar abscess 
discharging at the cervical margin of the gum. The former may be differ- 
entiated by the absence usually of cervical deposits except in the later 
stages of the disease, nearly normal attachment of the gingival margins, 
hematogenic deposits found high up in the pockets towards the apex 
of the root, the history of a painful swelling (abscess) upon the gum, and 
periodic soreness of the tooth. This may be supplemented by the family 
and personal history which give evidences of other gouty conditions. 

The latter may be differentiated by applying those tests to determine 
the vitality of the teeth which have been mentioned in the chapter on 
"Pulpless Teeth." 

Prognosis. — Very little encouragement can be given as to the perma- 
nent conservation of those teeth which have been once attacked by this dis- 
ease ; and yet by a judicious system of general and local treatment, which 
shall build up the debilitated condition of the body, and if possible re- 
establish normal function in the various excretory organs and place the 
teeth and the mouth in the best possible hygienic condition, much may be 
hoped for in the way of controlling the progress of the disease. 

But the common history of such cases reveals the fact that sooner or 
later the teeth are lost. When the disease assumes an acute type the 
affected teeth may be lost in a few months ; when the chrOnic form prevails 
the ultimate loss of the teeth may compass many years. 

Treatment. — Treatment will prove of little benefit if it is applied to 
the correction of the local symptoms only ; for inasmuch as the disease is 
influenced by or is largely due to certain abnormal states of the general 
system, it stands to reason that these abnormal conditions must be cor- 
rected if local treatment is to be of any real value. 

It is best, therefore, at the beginning to call for a consultation with the 
family medical adviser and go over the case together, and then decide 



574 OPERATIVE DENTISTRY. 

upon the line of general treatment which the particular case requires, 
leaving the conduct of this part of the case in the hands of the physician, 
while the dentist addresses himself to the local treatment of the oral mani- 
festations. By such co-operation between the general practitioner and the 
oral specialist a much better service can be rendered the patient than if 
each wrought upon the case independently and with no harmony of action. 

The local conditions which demand correction are malocclusion, extru- 
sion or rotation of the tooth, loss of antagonizing teeth, undue mobility., 
the presence of suppurative discharges and carious alveolar structure, 
foreign deposits, inflammation of the gums, and general unhygienic con- 
ditions of the mouth. 

Malocclusions are, without doubt, responsible for the establishment of 
the disease in many instances by exciting congestion and other inflamma- 
tory symptoms in the peridental membrane. The correction of the mal- 
occlusion by simply grinding off the opposing tooth or dressing down a 
filling will often give immediate relief and arrest the further progress of 
the disease for a considerable period. 

Extrusion and rotation of the teeth upon their axes is often arrested in 
the same manner, for many such cases have their origin in a malocclusion. 
Certain cases, however, seem to be dependent upon the inflammatory dis- 
turbances of the peridental membrane, the malposition increasing with 
the inCTeasing destruction of the pericementum. 

Drs. M. L. Rhein and D. D. Smith have both recommended as a remedy 
for the correction of the abnormal conditions which produce this shifting of 
the teeth the devitalization of the pulp. It is argued that by devitalizing 
the pulp the supply of blood which was originally intended for the pulp is 
directed to the peridental membrane, and the threatened degeneration of 
this structure thereby averted. The argument seems good, and clinic ex- 
perience tends to substantiate the argument, although there have not been, 
to the knowledge of the writer, any corroborated histologic data presented 
in proof. 

Loss of antagonizing teeth is a most prolific source of extrusion of the 
bicuspids and molars. The loss of a tooth from any cause throws its 
opposing fellow into disuse, and thereby predisposes it to certain diseases 
of the pericementum like atrophy and degeneration. The substitution of 
the lost teeth by a bridge or a plate often corrects these tendencies if taken 
in time. 

Undue motility should be corrected by ligaturing, wiring, or splinting, 
after the manner already described. Excessive mobility of the tooth in- 
creases the irritation of the peridental membrane, and by that much aggra- 
vates the already existing morbid condition. 

Local treatment directed to the removal of deposits and necrotic tissue, 
and the sterilization of the pockets, will be of greater benefit if the teeth 
can be held firmly in place — put at rest —during the healing process. 

The treatment of the pockets is an important feature in these cases. 
Various opinions are held upon this part of the subject. Black * is cautious 

* American System of Dentistry, vol. i. p. 981. 



PHAGEDENIC PERICEMENTITIS. 575 

not to injure the gum margin in the removal of the deposits, but when 
once beyond the gum margin to use vigorous means to remove the concre- 
tions, not fearing to injure the tissues which line the pocket. Burchard* 
also offers the same suggestion. The writer has found au opposite course 
of treatment in reference to the gum margins to give the best results. This 
plan of treatment was suggested more than twenty years ago by studying 
certain cases in which, by atrophy or ulceration of the gum overlying the 
root of a tooth, the pocket had been obliterated and a spontaneous cure 
established. This evidently was nature's method of arresting the progress 
of the disease, and therefore it seemed safe to follow her leadings. From 
that time to this the writer has employed it many times, often with 
the very best results, and has to-day cases under observation which were 
treated by this method fifteen to eighteen years ago, and are still doing 
good service. Not all cases, not even a majority so treated, however, 
prove successful ; but where the general condition of the system can be 
built up to normal tone, and the patient will keep the mouth in a hygienic 
condition, the best results follow. 

The method is to excise the gum down to the bottom of the pocket 
by removing a Y-shaped flap, the apex of the flap pointing towards the 
apex of the root. This exposes the denuded surface of the root and the 
carious edge of the alveolus, and makes it possible after the hemorrhage 
has ceased to find all of the concretions, remove the ulcerating pericemen- 
tum, and curette the carious alveolar margins. It also secures perfect 
drainage and makes sterilization easy. 

Objection has been raised to its employment upon the labial aspect of 
the anterior teeth, and for cosmetic reasons the objection is valid. An 
exposed root, with a healthy pericementum, alveolus, and gum surrounding 
it, is, however, a thousand times better than leaving the gum intact and 
with it all the disgusting features of the disease. 

The first cases treated by this method were superior incisors having 
pockets upon the lingual aspect of the root. Some of these did so well 
that it was tried upon the palatal roots of molars, and, as courage was 
gained, to all of the teeth in any location of the mouth. The method suc- 
ceeds best if done in the early stage of the disease, but it proves beneficial 
in all stages. The only serious objection to the operation being performed 
upon the labial surfaces of the roots of the anterior teeth is the one already 
mentioned, and for that reason, if the patient has a short lip and shows the 
gums in talking and laughing, it Avould prove an ugly disfigurement ; aside 
from this the ovjeration may be commended. In such cases as last described 
the gum may be slit open from the margin towards the apex, the flaps laid 
back to expose the carious margin of the alveolus, as suggested by Garret- 
son, and the gum afterwards brought together and closed by sutures. 

The instruments which are best adapted for curetting the alveolar 
border in this operation are hoe or spoon- bladed excavators with an angle 
of about forty-five degrees, or sharp chisels. During the operation the 
side of the blade should be kept close to the root in order that the gum- 

* Dental Pathology, Therapeutics, and Pharmacology, -p. 475. 



576 



OPERATIVE DENTISTRY. 



Fig. 642. 

® e • 
ft 



Dr. Allport' 
bur. 



tissue may not be unnecessarily injured. The same instruments are valu- 
able for curetting the alveolus in any form of operation that may be 
adopted. 

The late Dr. Allport designed a bur (Fig. 642) for the especial purpose 
of curetting the alveolar border by passing the instrument into the pocket 
from the margin of the gum. This instrument permits the 
removal of the diseased border without unnecessarily injuring 
either the cementum or the overlying gum. The tapering en- 
r j largement of the instrument between the bur and the shank 

allows the head of the instrument to be kept close to the ce : 
mentum without cutting its surface, and insures the certainty 
of a complete removal of all the carious portions of the alveolus. 
Effort should be made also to freshen the margin of the 
pericementum by passing a delicate hoe-shaped instrument of 
the pattern just described to the bottom of the pocket and 
sweeping around the denuded edge of the alveolar plate. The 
pus, blood, and the debris of the operation can be cleared out 
of the pocket by irrigating it with hydrogen dioxide, and then 
sterilizing with a 1 to 500 solution of mercuric chloride in water, or the 
same strength solution may be made in hydrogen dioxide. The Dunn 
medicinal syringe is a most convenient instrument for the purpose of irri- 
gating such pockets and of applying other liquid remedies. 

Caustic and escharotic remedies should be avoided after such an opera- 
tion, as in a majority of cases the application of such powerful agents 
would prevent the process of granulation by paving the way for the pro- 
duction of more necrotic tissue in the very location in which a moment 
before so much pains had been taken to remove it. Such kind of treat- 
ment in general surgery would only be considered permissible in cases of 
malignant disease where the surgeon felt that there was quite strong pre- 
sumptive evidence that all of the malignant tissue had not been removed. 
But if applied under any other circumstances he would expect to find his 
efforts to produce healing of the wound defeated by the presence of necrotic 
tissue, which must be again removed before regeneration could take place. 
Black recommended making a semicircular incision in the gum over 
the carious alveolar border, raising the flap and operating through this 
opening with sharp chisels, and, after irrigation with hydrogen dioxide, 
stitching the flap in position. The main object of this operation is to 
remove the carious material without injuring the gum margin. 

The after-treatment should consist of thorough hygienic care of the 
mouth and the use of antiseptic stimulating and astringent mouth lotions. 
Tincture of capsicum and myrrh, one part capsicum to four parts of 
myrrh (one teaspoonful to a goblet of water), is one of the best stimu- 
lating and astringent lotions for this purpose. 

Replanting. — Treatment of this disease by extraction and replanting 
has been recommended from time to time, but the operation has met with 
such indifferent success that it has never become a popular method of 
treatment. The writer some ten years ago made several of these opera- 
tions in dispensary and private practice, and although at first they gave 



PHAGEDENIC PERICEMENTITIS. 577 

great promise of a successful issue, all of them were lost inside of two 
years as the result of the recurrence of the disease in an acute form follow- 
ing slight injuries. The methods adopted were the same as those described 
in the chapter on dento-alveolar abscess. 

Sponge-Grafting.— Dr. E. C. Briggs* and the late Dr. W. H. Atkin- 
son f first called attention to the use of sponge-grafts to reproduce tissue 
lost by this disease, and while successes were undoubtedly obtained under 
favorable conditions of oral hygiene, the great majority of such operations 
in the mouth were failures, because of the difficulty in obtaining and 
maintaining aseptic conditions. 

Electricity. — The employment of electricity in its various forms is 
sometimes beneficial in the treatment of those cases of the disease which 

Fig. 643. 



Improved den to-electric cautery. 

are free from deposits. The writer has found the best results to follow the 
application of the galvanic cautery to the diseased tissues of the pockets, 
and afterwards applying a mild faradic current to stimulate the circu- 
lation of the pericemental membrane. 

Before applying the cautery a ten per cent, solution of cocaine should 
be applied to the pocket. Eucaine or chloretone in proper strength will 
answer an equally useful purpose, and be less liable to produce unfavorable 
constitutional impressions. After the gum has become anaesthetized the 
cautery-point (Fig. 643) may be applied and the current turned on for a 
sufficient space of time to permit the cauterizing of the margin of the peri- 
cementum, the whole surface of the pocket, and the carious border of the 
alveolus. The parts should next be irrigated, and instruction given to 
the patient to keep the mouth thoroughly clean by the use of antiseptic 
lotions, etc. The cauterized tissue sloughs away in a day or two and 
healthy granulations appear upon its surface. The faradic current may 
now be employed to stimulate the sluggish circulation of the pericemental 
membrane by applying the anode to the gum over the affected root and 
the cathode to the external surface beneath the jaw. 

The current employed should never be strong enough to be unpleasant. 
The duration of the treatment may be from ten to twenty minutes. Catapho- 
resis may also be employed with cocaine to produce local anaesthesia, and 
also to obtain diffusion of such drugs as are employed to stimulate the dis- 
eased tissues to a more healthy functional activity. 

* Transactions American Medical Association, 1884. 

t Transactions American Dental Association, 1885, pp. 152-154. 

37 



CHAPTEE XLL 



ANESTHETICS, LOCAL AND GENERAL. 



Definition. — Anaesthetic (Greek, dv, priv., and aladdvzadai, to feel), a 
substance that produces insensibility to feeling or to acute pain, diminished 
muscular action, and other phenomena. 

Ancesthesia is a state or condition of insensibility or loss of feeling due 
to pathologic conditions of the nerve-centres, of the nerve-trunks, or of 
their peripheral terminations, or to the artificial production of insensi- 
bility by means of the toxic effect of certain substances which temporarily 
inhibit the sensory functions of the nerve-centres, of the conducting paths 

Fig. 644. 




Fprav apparatus— hand-instrument. 



of the nerves, or of their peripheral terminations. The former is termed 
pathologic ancesthesia, the latter surgical ancesthesia. Surgical anaesthetics 
are of two general classes, — viz., those which act locally at the point of 
application and are termed local anaesthetics, and those which act through 
the general system, termed general ancesthetics. 

Local Anaesthetics. — Various remedies have been introduced from 

time to time for the purpose of producing local insensibility to pain, 

especially for the extraction of teeth and other minor surgical operations. 

Most of these, however, have been discarded for various reasons, such as 

578 



ANESTHETICS, LOCAL AND GENERAL. 



579 



the unreliability of their anaesthetic power, their danger of producing 
general toxic effects upon the central nervous system, or their tendency to 
cause local gangrene and sloughing of the soft tissues. 

These remedies may be divided into two groups, — first, those ivMch 
produce anaesthesia by the local abstraction of heat ; and second, those which 
produce anaesthesia through their local narcotic effect upon the tissues to which 
they are applied. 

ANAESTHESIA BY THE LOCAL ABSTRACTION OF HEAT. 

Richardson Method. — Dr. B. W. Eichardson (1866) suggested the 
use of ether in a finely divided spray thrown upon the parts to be oper- 



Fig. 645.. 




Spray apparatus— foot-instrument. 

ated upon. This was accomplished by means of a hand or foot bellows- 
atomizer. Fig. 644 shows the hand- instrument ; Fig. 645 shows the foot- 



580 



OPERATI V E DE NTISTRY. 



instrument. The strongest ether is used, freed from alcohol and water, 
and mixed more or less with atmospheric air. The apparatus consists of 
a bottle to contain the ether, in the mouth of which a cork is fitted and 
perforated with two holes, through which a double glass tube is passed, 
one extremity of the inner part going to the bottom of the bottle ; above 
the cork a tube connected with the bellows pierces the outer part of the 
double tube and communicates by a small opening with the interior of the 
bottle at the inner side of the cork. The inner tube, reaching to the bottom 
of the bottle, delivers the ether at the extremity of the outer tube. 
Compression of the bellows produces two currents of air, one of which 
descends and presses upon the surface of the ether contained in the bottle, 
causing it to rise in the inner tube ; the other ascends through the outer 
tube and plays upon the column of ether as it ascends through the inner 
tube, converting the ether into a finely divided spray. 

The effect of the spray is to increase the rapidity of the evaporation, 
which produces intense cold, abstracting the heat of the tissues to such an 
extent as nearly to freeze them, and thus rendering them, for the time 
being, insensible to pain. 

Bhiffolene, which is a distillation product of petroleum, is used for the 
same purpose and by the same means. This substance is the lightest of 
all known liquids ; its specific gravity is 0.625, and it boils at 70° F. It 
volatilizes more rapidly than ether, and consequently reduces the tempera- 
ture of the tissues much more rapidly than does the ether. 

Special points for the atomizer have been devised for the use of the 
dentist, as shown in Fig. 645, which permit a spray to be thrown upon 
each side of the gum. 

Letamendi's Method. — Dr. Letamendi (1875) suggested an improve- 
ment upon Eichardson's method as follows : After applying a perfectly 
neutral sulphuric ether spray for about two minutes, he found the surface 
of the skin becomes red or hypersemic and is the seat of a disagreeable 
sensation of cold, but no sensation of burning in the part. At this stage 
of the process he made a slight incision in the centre of the hypersemic 
area with a convex-edged bistoury, eight to ten millimetres in length, but 
not going deeper than the capillary layer of the cutis. Almost immedi- 
ately there is produced an ansemic zone around the incision which enlarges 
outwardly. If the spray is again made to play for a few seconds over the 
surface which has become ansemic, the region becomes perfectly bloodless 
and completely anaesthetic. The advantage of this method is that the 
tissues become anaesthetic much sooner than by the Eichardson method, 
and there is not the danger of so reducing the temperature as to freeze the 
part and thus cause death of the tissue and sloughing. 

Dr. Letamendi offers the following theory to account for the effect of 
the slight incision made in the superficial structures of the skin.* ''The 
abstraction of heat caused by the application of the ether spray causes 
relaxation and consequently dilatation of the vessels. The incision pro- 
duces a sudden reaction, or stimulus, which converts the extreme dilatation 



Archives de Physiologie, 1875. 




ANAESTHETICS, LOCAL AND GENERAL. 581 

into an extreme contraction, which makes the anaemia and consequently 
the anaesthesia complete." 

Arnott suggested as a substitute for ether and rhigolene a freezing mix- 
ture composed of ice or snow and common table salt in the proportion of 
two parts of ice or snow to one of salt. To be most effective it should be 
enclosed in a bag, one side of which should be made of rubber sheeting 
and the other of a coarse meshed linen or cotton cloth, to permit the water 
formed by the melting of the ice to drain away. 

In applying the bag to produce anaesthesia of the gums preparatory to 
extracting a tooth, the cloth side should be placed in contact with the 
gums and tooth, the rubber side being against the cheek, thus protecting 
it from injury which might result from a reduction of the temperature. 
The briny fluid which accumulates in the mouth from the melting of the 
ice may be removed by the use of the saliva ejector. 

These agents have given place during the last few years to the use of 
ethyl chloride, or mixed ethyl and methyl chloride. Ethyl chloride is con- 
tained in glass tubes with capil- 
lary points and is exceedingly FlG - 646 - 
volatile. (Fig. 646. ) The spray 
is directed upon the gum over 
the tooth to be extracted until 
intense anaemia or ischaemia is 
produced, which is announced 
by the whiteness of the tissue, 
when it will be found to be in a state of analgesia or anaesthesia. 

Ethyl chloride is inflammable and explosive, and must therefore be 
kept in a cool place and far from a flame. 

The danger from these methods lies in the fact that if great care is not 
exercised in applying the spray, the vitality of the tissues may be destroyed 
by reducing the temperature to a lower degree than living tissues can 
endure. 

It is interesting to note in this connection the high and low degrees of 
temperature that are safely tolerated by vital tissues. If the temperature 
be raised above 130° F. or 140° F., and maintained for any considerable 
period, death of the tissue is the inevitable result. Higher temperatures 
act still more rapidly. If the temperature be lowered to 60° F. or 65° F., 
and maintained for any considerable time, the vitality of the tissue will be 
destroyed. (Ziegler.) Much higher and lower degrees of temperature can 
be safely borne by the tissues if they remain at these temperatures but 
for a short time. The prolonged application of the hot- water bag or of the 
ice-bag frequently causes death of limited areas of soft tissue, which slough 
and are sometimes slow to heal. 

ANAESTHESIA BY THE LOCAL NARCOTIC EFFECT OF DRUGS. 

Cocaine. — "Cocaine is the chief alkaloid extract of erythroxylon coca, 
and when applied locally it is a powerful anaesthetic in a limited area. 
It resembles caffeine in its action on the nerve-centres, and atropine in its 
effects upon the respiratory and circulating organs. Its action is most 



582 OPERATIVE DENTISTRY. 

rapid upon mucous tissues. Applied to the conjunctiva, it dilates the 
pupil and paralyzes the function of accommodation.' 1 

The introduction of cocaine hydrochlorate as a local anaesthetic has to a very 
large extent superseded all substances previously employed for this purpose. 

When cocaine was first used for the purpose of producing anaesthesia 
for tooth extraction, it was applied to the surface of the gum, but its anaes- 
thetic effect did not extend beyond the mucous membrane, consequently it 
proved of little value, as it did not render the operation painless. Later 
it was employed hypodermatically in solution, when the tissues so infiltrated 
were found to be rendered completely anaesthetic. 

Immediately following its employment by hypodermatic injection, many 
cases were reported of the development of unpleasant and serious consti- 
tutional symptoms, and not a few fatal cases have been recorded as the 
result of paralysis of the respiratory and cardiac functions. 

These serious symptoms and fatal results demonstrated the fact that 
cocaine was one of the actively poisonous vegetable alkaloids, and that its 
use must be restricted to such persons as were free from pulmonary and 
cardiac diseases, and that the dosage needed to be greatly reduced when 
applied hypodermatically. 

It had been customary at this time to prescribe cocaine per stomach in 
doses of from half a grain to one grain, and hypodermatically from one- 
fourth to one-half a grain. The doses now administered by the stomach 
are from one-fourth to three-fourths of a grain, and hypodermatically from 
one-twelfth to one-eighth of a grain. The larger-sized dose cannot be ex- 
ceeded with safety to the patient. 

The poisonous effects of cocaine are manifested upon the respiratory 
and cardiac centres, and when long continued, as in the " cocaine habit," 
it produces insomnia, moral and intellectual decay, emaciation, and death. 

Its action is at first stimulating, and afterwards narcotic and depressing. 
When administered in a fatal dose it acts by paraly zi ng the respiratory 
and cardiac functions. The physiologic antidote is morphine. To neu- 
tralize the toxic effect of cocaine upon the respiratory centres, it is not 
necessary to administer a full dose of morphine ; one-twelfth of a grain is 
sufficient for the purpose. 

To neutralize the toxic effect upon the heart and arteries, which is mani- 
fest in the form of tonic spasms of the muscles of these organs, one drop 
of a one per cent, solution of trinitrin may be added to each dose adminis- 
tered hypodermatically. 

Curtis* regards volasem — an extract of violets — as the ''natural anti- 
dote" of cocaine. He claims for the drug that it neutralizes the general 
toxic effect of the cocaine while it does not interfere with its local effect. 
It acts by stimulating the heart action and the respiratory movements, 
contracts the arterioles, and raises the blood pressure. Administered in 
five-drop doses immediately before the cocaine injection, it is claimed to 
effectually prevent the general toxic effects of this drug, and in cocaine 
poisoning is an efficient antidote. 

* International Dental Journal, 1900, p. 613. 



ANESTHETICS, LOCAL AND GENERAL. 583 

Experience in the use of cocaine administered hypodermatically for the 
extraction of teeth and other minor surgical operations has proved that 
the smaller dose — one-twelfth of a grain and even less — is just as effective 
in producing a local anaesthesia as is the larger dose ; while by the employ- 
ment of the smaller dose the dangers of developing constitutional symp- 
toms are entirely overcome, except in those cases in which there exists an 
idiosyncrasy against this drug. 

The writer has found from a large experience with cocaine, both in the 
extraction of teeth and in surgical operations, sometimes of considerable 
magnitude, like the extirpation of cancerous growths of the lips and jaws, 
that a one or two per cent, solution of cocaine is just as efficient as a four 
or even a ten per cent, solution. When the area to be anaesthetized is 
large and there is a possibility of exceeding a medium dose, a one per 
cent, solution may be employed. In extracting teeth, two to three minims 
of a two per cent, solution should be injected upon each side of the jaw, 
care being taken to keep the needle close to the alveolar process, as by this 
method better results are obtained than when the injection is made nearer 
the external surface. In operations for the removal of tumors, a one per 
cent, solution can be used, but double the quantity employed, and the in- 
jections made at several different points. The one-twelfth of a grain dis- 
solved in a drachm of sterilized water is more efficient than the same dose 
in one-half the quantity of the menstruum. 

By using a standard solution the dose may always be accurately gauged, 
and the possibility of an overdose being administered entirely obviated. 

The galvanic current as applied in cataphoresis hastens the anaesthetic 
action of the drug and makes it more profound. For the methods of its 
application the reader is referred to the chapter on Hypersensitive Dentin. 

Cocaine solutions are liable to spoil, if kept for any length of time, by 
the development of fungi. It therefore becomes necessary to add an effi- 
cient antiseptic to solutions that are intended to be permanent, as sterili- 
zation by heat cannot be employed without producing chemic changes in 
the cocaine which destroy its character. Boiling causes it to split up into 
methyl, benzoic acid, and ecgonine. By using a one-half per cent, solution 
of carbolic acid as the vehicle for making the cocaine solution the devel- 
opment of fungi is entirely prevented, and such solutions will keep for 
weeks without change. 

Burchard recommends the following prescription : 

R Cocainse hydrochloric!. , gr. £ ; 
Morphinse sulph., gr. T \ ; 
Or atrophias sulph., gr. T io ; 
Trinitrin (one per cent, solution), gtt. i ; 
Acidi carbolici, gtt. i ; 
Aquas, ad q. s. 
Sig. — The above represents. a half-syringeful, and is a full dose. 

Tropacocaine is derived from the small-leaved coca of Java. It pos- 
sesses a decided advantage over cocaine as a local anaesthetic in that it is 
considerably less toxic in its effects, has but a slightly depressant action 
upon the cardiac functions, and is free from any paralyzing effect upon the 



584 



OPERATIVE DENTISTRY. 



function of respiration. As an anaesthetic it is more rapid in its action 
than cocaine, but it is not so persistent in its effects. The dose is from 
one-third to two-thirds of a grain. It is made in solution with sterilized 
water, and the drug is of itself slightly antiseptic. 

Eucaine. — Eucaine hydrochlorate "A" is a synthetic body of similar 
chemical constitution as cocaine, and the observed similarity in this re- 
spect was the means of causing experimentation with it as to its value as 
an anaesthetic and mydriatic. It is a white, neutral, crystalline powder, 
soluble in ten parts of cold water, about nine per cent. It is preferred by 
many ophthalmologists to cocaine for all purposes in which this drug is 
used, as its toxic effects are less powerful, while its anaesthetic and mydri- 
atic powers are more persistent than those of cocaine. 

Its physiologic effect upon the central nervous system is primarily 
one of exaltation, as shown in a quickened heart-beat, and secondarily of 
depression and paralysis. Locally it produces hypereemia of the capilla- 
ries, while cocaine produces ischsemia. 

Solutions of eucaine are made in distilled water, and are much more 
stable than those of cocaine. Sterilization by boiling does not decompose 
the eucaine. The maximum dose hypodermatically is from one-fourth to 
one-half a grain. It is employed in dental surgery in from four to nine 
per cent, solutions. Solutions stronger than nine per cent, are not stable, 
and will separate crystals of eucaine. 

Beta Eucaine. — Eucaine hydrochlorate U B'' is a similar synthetic body 
to eucaine "A." It is a white, neutral crystalline powder, soluble in from 
twenty-seven to twenty-eight parts of cold water — three to four per cent. — 
at ordinary room-temperature. The toxicity of eucaine "B," according to 
the experiments of Drs. Dumont and Legrand, is 3.75 less than that of 
cocaine, and about three times less than eucaine " A," while its anaesthetic 
effect is equally rapid, but of shorter duration. It is complete in from 
three to five minutes, and disappears in from ten to twenty minutes. 
Later experiments place the toxic effect of eucaine " B" at five times less 
than that of cocaine. It is employed hypodermatically in dental surgery 
in solutions of one-tenth to one per cent. The dose usually employed is 
one to two centigrammes (one-sixth to one-third of a grain) of a one per 
cent, aqueous solution. 

Ghloretone (acetonchloroform, or trichlor tertiary butyl alcohol) is an- 
other synthetic compound, prepared by Parke, Davis & Co., and "is 
formed when caustic potash is slowly added to equal weights of chloroform 
and acetone, and may be isolated from this mixture, after the removal of 
any excess of acetone and chloroform, by distilling with steam. Obtained 
in this manner, it is a white, crystalline compound, having the odor of 
camphor. When freed from water by melting and allowed to cool, the 
camphoraceous odor is more pronounced, and its general appearance re- 
sembles camphor more closely. It is very soluble in chloroform, acetone, 
strong alcohol, ether, benzine, and glacial acetic acid, sparingly soluble in 
cold water (one per cent.), more soluble in boiling water. Dilute acids 
and alkalies are apparently without effect ; concentrated sulphuric acid 
decomposes it." (Houghton and Aldrich.) 



ANAESTHETICS, LOCAL AND GENERAL. 585 

Chloretone possesses hypnotic and general and local anaesthetic proper- 
ties. Its general effects are mainly confined to the central nervous system, 
differing only from most of the other hypnotics and anaesthetics of the fatty 
acid series in that it has little or no depressing effect upon the circulatory 
system. Experimentation has shown that chloretone has a selective action 
for the central nervous system, as more of this drug was found in the brain 
in several instances than in any other organ of the body. Its local anaes- 
thetic properties are of a high order and in many respects resemble those 
of cocaine. It also possesses marked antiseptic properties, and for this 
reason is free from the objection sometimes raised against solutions of 
cocaine used for hypodermatic injection, — viz., that abscess and sloughing 
sometimes follow its employment. 

Chloretone may be used hypodermatically in all cases where cocaine 
can be employed, while it is free from the serious objection to cocaine in 
that it has little or no depressing effect upon the action of the heart. 

In dental surgery it may^be employed locally for obtunding hyper- 
sensitive dentin and producing anaesthesia of the dental pulp preparatory 
to its surgical extirpation and for the extraction of teeth. For obtunding 
hypersensitive dentin and anaesthetizing the pulp, a solution is prepared 
by mixing equal parts by weight of sulphuric ether and chloretone crystals. 
This is applied upon a pledget of cotton after the rubber dam has been 
adjusted. It may also be applied cataphorically after the manner of 
cocaine. 

For extracting teeth, a solution may be prepared by mixing fifteen per 
cent, of alcohol with eighty-five per cent, of distilled water, and adding 
enough chloretone to form a saturated solution. (Leo.) The dose of this 
solution (one per cent.) hypodermatically is from fifteen to twenty-five 
minims, and the full local anaesthetic effect is obtained in from one to three 
minutes. The dose of the crystals per stomach for its anodyne and hyp- 
notic effect is from five to fifteen grains, administered in capsules or 
tablets. 

In the employment of anaesthetic drugs which are applied by hypoder- 
matic injection, the operation must be performed under the strictest anti- 
septic precautions, in order to preclude the possibility of septic infection. 

The surface to be punctured should be cleansed and rendered aseptic 
by repeated washing with one of the common antiseptic solutions. The 
syringe should be of metal throughout — cylinder and piston— so that it 
may be sterilized by boiling ; any other form of syringe cannot be sub- 
jected in all of its parts to such a process without spoiling it, and unless so 
treated it is unsafe to use. The solutions employed should also be sterile, 
otherwise abscesses may follow their injection into the tissues. 

The immediate dangers from the hypodermatic injection of any of these 
drugs are their toxic effects, and these may develop at any time and when 
least expected. The operator should therefore be prepared at all times 
with such remedies as may be useful in combating these effects. 

The symptoms of cocaine poisoning are dizziness and sense of faintness, 
great pallor, rapid and feeble pulse, bluish- white lips, cold perspiration, 
spasmodic respirations, and syncope. To combat these symptoms, diffusi- 



586 OPERATIVE DENTISTRY. 

ble stimulants are called for, such as aromatic spirit of ammonia and 
whiskey or brandy. 

The aromatic spirit of ammonia may be administered in doses of from 
one-half to one fluidounce in water, or whiskey or brandy in doses of 
from one to two fluidounces. If the patient cannot swallow, one-half of 
this amount of whiskey or brandy may be administered hypodermatically. 
When the heart action is very weak, sulphate of strychnine, one-hundredth 
of a grain in a drachm of whiskey, or digitalin in doses of from one- 
hundredth to one-fiftieth of a grain, may be administered hypoderinatically. 
The tendency to fatal syncope may be combated by the inhalation of amyl 
nitrite in doses of from two to three minims dropped upon a napkin and 
held under the nose. This remedy is also put up in tiny glass flasks or 
pearls containing three minims each, which may be crushed upon a napkin. 

If these measures fail, artificial respiration and electricity should be 
employed, and further stimulation of the nerve-centres attempted by the 
hypodermatic injection of nitroglycerin in doses of one-half minim to one 
minim of a one per cent, solution, increased 'to two minims if necessary. 

GENERAL ANAESTHETICS. 

The substances which are commonly used for the purpose of producing 
general amesthesia are chloroform, ether, and nitrous oxide gas; various 
other substances have been introduced and tried for the same purpose, but 
none of them has ever enjoyed popular favor. Among these substances 
may be mentioned amylene (pental), carbon tetrachloride, chloral hydrate, ethene 
chloride, hydrobromic ether (bromide of ethyl), and various mixtures of alco- 
hol and chloroform, and alcohol, chloroform, and ether. 

The substances which are most commonly used in the practice of dental 
surgery are nitrous oxide gas (N 2 0) and sulphuric ether (C 2 H 5 ) 2 0. Chloroform 
(CHCI3) is rarely used in the extraction of teeth or other operations which 
require for their performance a sitting position, on account of the depress- 
ing effect of the drug upon the functions of the heart. These dangers are, 
however, greatly lessened if the patient can be kept in a recumbent posi- 
tion during the entire period of anaesthesia. Infants and little children 
bear chloroform better than adults, and in many ways it acts more kindly 
upon little children than any other anaesthetic. Chloroform has proved 
itself to be so unsafe for dental operations upon adults that it is rarely 
used at the present time for these purposes. Nitrous oxide gas and ether 
are so much safer, and so completely fill the requirements of anaesthetics in 
both brief and prolonged operations, that there is no need of running the 
risk of a fatal accident by employing chloroform when comparatively safe 
remedies may be used in its stead. 

Nitrous Oxide Gas. — This substance is the safest of all of the anaes- 
thetics employed for dental purposes that have so far been discovered. 
It suffers no chemical change at the temperature of the body or during its 
inhalation. Its only drawback is the fact that the anaesthesia produced by 
it is of such short duration — usually from thirty to sixty seconds— that it 
can be employed only in momentary operations, like the extraction of 
teeth, the lancing of an abscess, or the extirpation of a vital pulp. For 



A.VESTHETK'S, EOCAL AND GENERAL. 



587 



this reason it has but little place in general surgery. It has been used in 
operations for strabismus, the removal of small tumors, for painful exami- 
nations, the setting of a recent luxation, or the performance of a tenotomy ; 
but in all operations requiring more than a very few minutes ether is to 
be preferred, as with this substance anaesthesia may be maintained for an 
hour or two if required. 

Nitrous oxide gas is made by the fusion of granulated ammonium nitrate 
in a glass retort, the gas being passed through three wash-bottles contain- 
ing water and collected in a small gasometer. 

The manufacture of the gas requires very close attention to obtain it in 
a pure state. The most common impurities likely to be found in the gas 
are chlorine and nitric oxide, and for this reason every sample of ammo- 
nium nitrate used should be tested for chlorine before using it, and the 
greatest care exercised not to allow the heat to rise above 482° F. , as nitric 



Fig. 04/ 




Fig. 64S. 




oxide is given off above this degree of heat, For the complete process of 
its manufacture the reader is referred to works on chemistry. 

Since the introduction of liquefied nitrous oxide gas few dentists 
manufacture the gas for themselves. The liquefied gas is so universally 
pure, that the dentist feels he can obtain a better article than he can manu- 
facture for himself ; while it is in such a convenient form to handle, and 
the apparatus takes up so little space in the operating-room, that there is 
no longer any need of his consuming his time in its manufacture or filling 
his office with a cumbersome apparatus. 

Nitrous oxide gas, when properly employed, is almost, if not entirely, 
free from danger, and is rarely productive of those disagreeable symptoms 
of nausea and depression which so commonly follow the administration of 
ether and chloroform. 

There are several forms of apparatus used for administering nitrous 
oxide, both for that made in the usual manner and for the liquefied gas. 
Fig. 647 represents one of the most commonly used office apparatuses, while 



588 



OPERATIVE DENTISTRY. 



Fig. 648 represents a portable apparatus which may be carried in the hand. 
In the former the condensed gas is discharged from the cylinder into "a 
gasometer, and the gas drawn from the gasometer through a flexible rubber 
tube and the inhaler. In the latter the gas is discharged into a rubber bag 
to which are attached a flexible rubber tube and an inhaler. The inhaler is 
the most important part of the apparatus, and should be so constructed as 




to admit or exclude air at the will of the operator. It should also be 
armed with a stop-cock by which the gas may be turned off, and an auto- 
matic valve whereby the expired air may be expelled and prevented from 
entering and mixing with the gas as it passes through the inhaler. 

Fig. 649 represents an inhaler with a removable lip-shield, while Fig. 
650 represents an inhaler having a face-piece or hood which covers not only 



Fig. 650. 



Fig. 651. 




the mouth, but the nose as well. The advantage of the former lies in the 
fact that when the lip-shield is removed the lips can be lightly compressed 
around the mouth-piece by the fingers of the operator, and it also gives a 
full view of these parts, so that the changes in their color, as shown in the 
mucous membrane, can be carefully watched and those symptoms noted 
which indicate the lack of oxygen and the accumulation of carbonic acid 



ANAESTHETICS, LOCAL AND GENERAL. 



589 



in the blood. Cyanosis of the lips, stertorous breathing, and jactitation, 
etc., are the danger signals. In the latter instrument the face-piece or hood 
is a serious disadvantage, in that it covers the mouth and nose, making it 
impossible to watch the effects of the gas upon the blood, while in those 
patients who wear a beard it is impossible to exclude the admission of air. 
Occasionally, as in cases of harelip, or when the orbicularis oris muscles 
are so much swollen that it is impossible to close the lips about the mouth- 
piece, the hood becomes of great service. Fig. 651 shows the mechanism 
of the inhaler. 

Hewitt's Method. — Dr. Hewitt, of London, England, believing that 
the symptoms of asphyxia which so often accompany the administration 
of nitrous oxide gas might be overcome by the admixture of a proper 
amount of oxygen with the gas, devised an apparatus by which oxygen can 
be mixed with the gas in various proportions. 

The apparatus (Fig. 652) consists of three cylinders of compressed gas, 
two filled with nitrous oxide and one with oxygen, the valves of which are 

Fig. 652. 




under the control of the foot of the operator. Connecting the cylinder 
with the rubber inhaling-bag, which is divided into two compartments by 
a rubber septum, is a double tube for conveying the gases to the bag. To 
the upper end of the inhaling-bag is attached a mixing- chamber, and to 
this is attached the mouth-piece or inhaling-tube. 

When about to administer the gas, the valves of the mixing -chamber 



590 



OPERATIVE DENTISTRY. 



Fig. 653. 




are closed. Oxygen is then let into one compartment of the inhaling-bag 
until it is nearly full and nitrous oxide into the other. The inhaling-tube 
is then placed in the mouth of the patient, who is instructed to make long, 

full, deep, and steady inspirations 
and expirations, the nose being 
closed with the thumb and finger 
of the operator, and the valve of 
the mixing- chamber (Fig. 653) so 
changed that only air is breathed 
for a few inhalations. The indi- 
cator is then pressed downward to 
the notch, which cuts off the air, 
and the patient now breathes only 
the pure nitrous oxide. After a 
few inhalations the indicator is 
carried still further downward to 
the second notch, which permits the 
passage of one part of oxygen to 
mix with the nitrous oxide. If the 
indicator is carried downward to the 
third notch, two parts of oxygen are 
mixed with the nitrous oxide, and 
so on until the patient receives the 
amount of oxygen necessary to pre- 
vent the appearance of the symptoms of asphyxia. The amount of oxygen 
required to prevent these symptoms varies considerably with each indi- 
vidual ; some require more, others less, and the amount varies also with 
the stage of the anaesthesia. The first symptom and the best guide to the 
condition of asphyxia is the cyanotic appearance of the lips and face. 

Similar advantages may be gained by the admission of atmospheric 
air in proper quantity and at the right time during the production of 
anaesthesia, but it is not possible to prolong the anaesthesia for so long a 
period as by the Hewitt method. 

EXAMINATION OF THE PHYSICAL CONDITION OF THE PATIENT. 

Before administering a general anaesthetic the condition of the patient 
should be ascertained by a critical physical examination, and if there is 
found to be present any serious functional or organic affection of the heart, 
of the lungs, or of the kidneys, ether and chloroform are contraindicated. 
Nitrous oxide may, however, in some of these cases be used with success, 
but there can be no positive assurance that a successful issue will follow its 
administration. It is better, therefore, in all such cases as would naturally 
come under the care of the dental surgeon for operation in which serious 
diseases of the heart, lungs, or kidneys exist, to use a stimulant to brace 
the patient for the ordeal of the operation, rather than to take the chances 
of administering an anaesthetic. 

The shock incident to the extraction of a tooth or the lancing of an 
alveolar abscess may be prevented in great measure, if not completely, by 



ANAESTHETICS, LOCAL AND GENERAL. 591 

the administration of stimulants or anodynes to such patients as cannot 
with safety take an anaesthetic. 

Ether is positively contraindicated in bronchial and pulmonary dis- 
eases and in diseases of the kidneys, and chloroform in diseases of the 
heart. For surgical operations which must be performed to save life, ether 
is the safest anaesthetic for patients suffering from functional or organic 
disease of the heart, while chloroform is safest for those suffering from 
bronchial and pulmonary diseases and affections of the kidneys. If the 
dentist does not feel that he is competent to decide the question of the 
physical condition of the patient, he should consult with the family physi- 
cian in relation to the matter, and if the patient has no family physician, 
it is best to divide the responsibility of the case by calling in some other 
physician to make the examination and administer the anaesthetic. 



PRECAUTIONS AGAINST ACCIDENTS. 

Anaesthetics should never be administered just after eating, as vomiting 
may be induced, and as a result particles of food may be drawn into the 
larynx on taking a deep inspiration and asphyxia be the result. 

If nitrous oxide is used, the dentist should never assume the double 
responsibility of administering the anaesthetic and performing the opera- 
tion alone. An intelligent and capable assistant should always be pres- 
ent. If ether or chloroform is used, the patient requires the undivided 
attention of the person who administers the anaesthetic, while the operator 
should not have his mind distracted by the care of the patient while under 
the anaesthetic. There is also another reason why in operating upon females 
under the influence of an anaesthetic the operator should not be alone, but 
should have another person present, preferably a nurse or a friend of the 
patient. Not infrequently hallucinations and erotic desires are stimulated 
by the effects of the anaesthetic, and the patient clings to the delusion that 
an indecent assault has been made upon her while she was in a helpless 
condition from the anaesthesia. The operator, therefore, if he would guard 
himself against unjust reproach and a serious criminal charge, should see 
to it that some friend of the patient is present during the operation. 

Before beginning the administration of any general anaesthetic, the 
mouth should be examined for the presence of artificial teeth, especially 
partial plates, as failure to take this precaution has in several instances 
resulted in a fatality from the plate becoming dislodged and falling into 
the larynx or becoming lodged in the oesophagus. 

In the administration of nitrous oxide a mouth-prop (Fig. 654 or Fig. 
655) is necessary to keep the mouth open during the operation. This 
should be applied before the mouth-piece is placed in position, so that 
when anaesthesia is complete no time will be lost in efforts to pry the mouth 
open to insert the prop. 

Props made of wood or vulcanite are the best ; they should have a 
long string securely fastened around the centre by which they may be 
withdrawn if by accident they should be dislodged and fall into the fauces. 

Clothing which is tight at the throat or the waist should be loosened, 



592 



OPERATIVE DENTISTRY, 



that there may be no obstruction to the most perfect movements of breath- 
ing. 

In the extraction of teeth, and particularly of roots, the operator should 
use the utmost care to prevent the tooth or root from slipping from the 
forceps and falling into the larynx, and when the elevator is used to dis- 

Fig. 655. 



Fig. 654. 






Mouth-prop (Dr. S. H. Guilford pattern). 



Dr. Daintree pattern. 



lodge a root, it should be removed from the mouth before another is 
extracted, for if left in the mouth it might fall into the larynx or be drawn 
in by a quick inspiration, and the patient die from asphyxia before it could 
be removed or relief obtained by tracheotomy. 



ADMINISTRATION OF ETHER. 

In favorable cases which require operations that consume more time 
than would be allowed by nitrous oxide anaesthesia, sulphuric ether is the 
safest and best anaesthetic that can be employed. This substance may be 

administered by means of a cone (Fig. 
Fig. 656. 656) formed of a towel or a folded news- 

paper, in which a napkin has been folded 
or a sponge has been placed and secured 
with an ordinary pin or a safety-pin. 
The napkin or sponge is saturated with 
ether, care being taken not to put on so 
much as to cause it to drip upon the face 
of the patient. It is then slowly advanced 
to the face of the patient, allowing plenty 
of air to be inspired with the ether vapor 
until the air-passages become accustomed 
to the irritation and the tendency to cough 
has passed away. It may then be brought 
close to the face and all air excluded ex- 
cept that which passes through the open 
end of the cone and through the sponge or over the surface of the napkin. 
In this way the patient receives a sufficient amount of oxygen to support 
the functions of life, while at the same time the air is thoroughly ini- 




Towel done up as a cone. 



ANAESTHETICS, LOCAL AND GENERAL. 



593 



pregnated with the ether vapor, and the patient is rapidly brought under 
its influence. 

Various forms of inhalers have been introduced from time to time for 
the administration of ether, the best of which are the Lente (Fig. 657) and 
the Allis (Fig. 658). 

The Lente inhaler is a cone made of sheet brass, fitted with a rubber 
air-cushion around the edge to exclude the air from entering between the 
cone and the face, while the upper end has an opening fitted with a cork- 
stoppered tube large enough to admit sufficient air. When in use the 
cone is lined with a piece of sheet lint or cotton, held in place by a piece 
of wire or whalebone slipped in, and long enough to curve upward, so as 
to keep the cotton from touching the face. The cotton lining is saturated 

Fig. 658. 



Fig. 657. 





Lente's inhaler, 



Allis's inhaler. 



with ether, and the apparatus is ready for use. Additional ether may be 
supplied through the open tube without removing the apparatus from the 
face, but great care must be exercised not to pour on more ether than the 
cotton will absorb, as there is danger of its running into the throat and 
causing asphyxia. 

The Allis inhaler ' ' consists of a wire framework sufficiently large to 
cover the lower part of the face ; these wires are parallel, and about one- 
quarter of an inch apart. Between the wires and from side to side a strip 
of muslin bandage, two and one-half inches wide and three yards long, is 
passed. The wire frame is five inches long by three inches at its greatest 
width. Outside of the wire frame there is a covering of sheet brass, and 
over this another metal cover with a cushioned edge to fit over the face, 
covering both the nose and mouth, as shown in Fig. 659. When ready for 
use, the top is left open for the free entrance of air and for supplying the 
ether from without." 

Many times, if the confidence of the patient can be secured beforehand, 
a tooth may be extracted, an abscess opened, or a pulp extirpated before 
the patient loses consciousness, as sensation to pain is lost long before this 
stage of complete anaesthesia is reached. In serious operations, however, 
profound anaesthesia is necessary in order to prevent shock and to obtain 
perfect control of the patient during the operation, as struggling or the 



594 OPERATIVE DENTISTRY. 

spasmodic contractions of the diaphragm and abdominal muscles incident 
to efforts to vomit caused by nausea are great hinderances to a delicate 
operation. 

During the stage of excitement or when the contractions of the abdo- 
minal muscles indicate the existence of a tendency to vomiting, the anaes- 
thesia should be hastened, in order to allay these symptoms and secure 
complete anaesthesia as quickly as possible. 

Complete anaesthesia may be recognized by placing the surface of a 
finger upon the conjunctiva of the eye, when, if sensation is not present, no 
contraction of the muscles of the lids will be observed. Complete relaxa- 
tion of the muscles is another indication of complete anaesthesia. This 
may be demonstrated by raising an arm, which will immediately fall if 
complete relaxation of the muscles has taken place. 

When the stage of muscular relaxation is reached there is a tendency 
for the lower jaw to drop and the tongue to fall into the fauces, which 

Fig. 659. 





Allis's aseptible ether inhaler, all met 



by its pressure upon the larynx and the glottis causes obstruction to 
breathing. This tendency of the jaw to drop may usually be overcome by 
placing the fingers upon its under side midway between the angle and the 
mental foramen, and bringing the teeth of the lower jaw in contact with 
those of the upper, and supporting it in that position. If the tongue falls 
into the fauces, it should be grasped with the tongue-forceps and with- 
drawn, and so held until muscular relaxation has passed. 

Dilatation of the pupil and stertorous breathing are danger signals, in- 
dicating that the limit of safety has been reached. The ether should there- 
fore be withdrawn, and the free administration of atmospheric air allowed. 
If the respirations cease and cyanosis of the lips and face is present, the 
tongue should be quickly grasped with a tenaculum or tongue-forceps, 
and the organ drawn well forward ; this opens the rima glottidis and allows 
free entrance of air. If, however, breathing does not immediately begin 
again, artificial respiration must be instituted and maintained until nature 
re-establishes the normal physiologic process. Other methods which may 
be employed to resuscitate the patient have already been described in an 
earlier part of this chapter under the head of cocaine anaesthesia. 



CHAPTER XLII. 

EXTRACTION OF TEETH. 

The operation of extracting teeth is one which requires experience, 
skill, good judgment, and an accurate knowledge of the anatomy of the 
teeth and of the contiguous parts. An operator who attempts to extract 
teeth without this exact knowledge will prove himself a bungler, and be 
the means of causing great suffering and irretrievable injury to the integ- 
rity of the remaining teeth and to the jaws. For these reasons it is very 
important that the operator thoroughly understand : 

1. The anatomy of the teeth and their most common anomalies. 

2. The relations of the roots of the teeth to the jaws. 

3. The indications which call for the extraction of teeth. 

4. The selection of the proper instruments with which to extract indi- 
vidual teeth or roots. 

5. The proper adjustment of the instrument to the tooth or root. 

6. The proper kind and direction of the force to be applied, and the 
lines of least and greatest resistance of the alveoli. 

7. The difficulties, complications, and accidents which are liable to 
occur in the operation. 

The anatomy of the teeth and their anomalies, and the relations of the 
roots of the teeth to the jaws, have already been discussed in Chapter I., 
to which the reader is referred. 

INDICATIONS WHICH CALL FOR THE EXTRACTION OF TEETH. 

The indications for tooth extraction are dependent upon such varied 
conditions, both local and general, that no arbitrary rules can be laid down 
by which to decide the many questions involved. All that can be done in 
this direction to assist the practitioner and the student is to suggest those 
conditions which most imperatively demand the operation. 

Deciduous Teeth. — There are certain conditions which demand the 
extraction of the permanent teeth which do not appear in relation with 
the temporary teeth by reason of their deciduous nature and function. 

The most important conditions which call for the extraction of the 
deciduous teeth are : 

1. When the teeth are the seat of alveolar abscesses which do not 
respond to appropriate treatment. 

2. When from other causes they are a source of continued irritation, 
affecting the comfort or the general health of the patient. 

3. When the retention of the deciduous teeth is causing the permanent 
teeth to erupt out of their normal position. 

4. When a deciduous tooth is retained long past the normal period for 
its exuviation by reason of the non- eruption of its permanent successor, 

595 



596 OPEEATIVE DENTISTRY. 

and it is becoming wedged between its immediate neighbors as a result of 
the approximal inclination of these teeth. 

Permanent Teeth. — The most important conditions which call for the 
extraction of the permanent teeth are : 

1. When a tooth or roots of a tooth are the subject of a chronic alveolar 
abscess which does not respond to treatment, or when there is in the upper 
jaw an abscess which discharges into the antrum or the nasal fossa. 

2. When a tooth is the subject of an acute alveolar abscess of malignant 
type, which threatens to cause acute septicemia. 

3. When a tooth is rendered useless from extrusion caused by the loss 
of its antagonist and a proper occlusion cannot be restored by artificial 
means, or it has become very loose from resorption of the alveolar pro- 
cess or from pyorrhoea alveolaris. 

4. When a tooth or the roots of a tooth have become useless for the 
purpose of crowning, bridging, or supporting a plate, by reason of the 
presence of fungoid growths of the pulp or the gum or of their gradual 
destruction by resorption. 

5. When a tooth is the subject of hypercenientosis which causes a per- 
sistent neuralgia. 

6. When a tooth is the subject of a persistent odontalgia dependent 
upon pulp-nodules or a pulpitis which does not respond to treatment and 
is causing serious reflex or constitutional irritation. 

7. When an erupting tooth is retarded by reason of insufficient room 
in the alveolar arch or the impingement of another tooth, and it is causing 
irritation and pain or acute deep-seated abscess of the jaw. This applies 
most often to the third molars, particularly those of the lower jaw. 

8. When it becomes necessary to sacrifice certain teeth to perfect the 
alignment of the dental arch. 

9. When the first permanent molars in children under eleven or twelve 
years of age — before the second molars are erupted — present with exposed 
pulps or alveolar abscesses. Under such circumstances all of the first per- 
manent molars had better be extracted, as such a procedure will result in 
a more perfectly formed arch and a better occlusion than if only the offend- 
ing tooth is removed. The writer is aware that there has been considera- 
ble discussion upon the advisability of such a course of treatment ; but he 
believes, after many years of experience and close observation of the re- 
sults of both of these lines of treatment, that the best results are obtained 
by the extraction of all of the first permanent molars. 

After the second molars have erupted the extraction of the first molars 
is unadvisable, except when the teeth are causing serious local or con- 
stitutional irritation, for after their removal there is a tendency for the 
second molar to tilt forward, forming an inverted Y-shaped space between 
itself and the second bicuspid, and preventing a normal occlusion of the 
mesial cusps. 

10. When it is necessary to remove certain sound teeth preparatory to 
inserting an artificial denture. 

Under such circumstances the teeth that should be removed are : (1) all 
roots which would be covered by the denture, except those which might be 



EXTRACTION OF TEETH. 597 

utilized to carry a crown or form an abutment for a bridge ; (2) all teeth 
which have been rendered unsightly or loose by reason of the resorption of 
the gums and the alveolar processes ; (3) all teeth that have become so far 
extruded from their alveoli as to render it impossible to place occluding 
artificial teeth in the opposing jaw ; (4) a single tooth or two teeth standing 
together, when they are the only teeth remaining in the upper jaw. This 
applies particularly to the incisors, cuspids, and bicuspids. Molars may 
often be left with advantage if they have occluding natural teeth ; (5) 
when one tooth remains upon either side of the upper jaw— if they are in 
good position and of proper shape to receive a clasp or give support to the 
plate — they should not be extracted ; (6) when a single tooth remains in 
the lower jaw, or a single tooth upon either side, it is advisable to retain 
them, especially if the patient is about to have inserted the first lower 
plate, as such teeth are valuable for supporting the denture by means of 
clasps, until such time as the patient becomes accustomed to it. 



GENERAL CONDITIONS UNFAVORABLE TO EXTRACTION. 

Certain systemic conditions are generally regarded as unfavorable to 
the extraction of teeth, for the reason that the operation may under these 
circumstances aggravate an existing morbid condition, set in operation a 
train of unfavorable symptoms, or establish a dangerous and perhaps fatal 
complication. 

The systemic conditions which are most liable to cause unfavorable 
results from the extraction of teeth are : 

I. General debility. 

II. Nervous irritability. 

III. Organic disease of the heart. 

IV. Epilepsy. 

V. Hemorrhagic diathesis. 

VI. Pregnancy. 

I. General Debility. — This is a condition which greatly predisposes 
the individual suffering from it to nervous depression and shock. In a large 
majority of these cases the vital forces are depressed, the nervous system is 
in an irritable condition, and the heart action weak. It therefore becomes 
necessary in these cases to prescribe tonic treatment in the form of iron, 
quinine, and strychnine, to prepare the patient for the ordeal of the opera- 
tion. If, however, an immediate operation is imperatively demanded, 
stimulants should be administered and the operation performed under an 
anaesthetic. 

II. Nervous Irritability. — General nervous irritability may be an 
inherited condition or diathesis, or one which is the result of morbid con- 
ditions of the system induced by disease, great nervous strain, overwork, 
and such like circumstances. In either case the affection is a manifestation 
of a debilitated condition of the nerve-centres calling for general tonic 
treatment, such as that just indicated, to build up the system ; and seda- 
tives, such as potassium bromide, asafetida, and valerianate of ammonium, 
to control the more irritable nervous manifestations. Operations upon such 



598 OPERATIVE DENTISTRY. 

individuals not infrequently result in severe shock to the nervous system, 
resulting in chorea, hysteria, or more serious nervous affections. 

III. Organic Disease of the Heart.— In organic disease of the heart 
in any of its many forms, — hypertrophy, fatty degeneration, valvular in- 
sufficiency, etc., — there is great danger of shock in even trivial operations. 
It therefore becomes necessary, whenever the operation of tooth-extraction 
is imperatively demanded, that every precaution be taken to guard against 
shock and its possible fatal termination. The nervous excitement and 
fright incident to the contemplation of the operation in individuals suffer- 
ing from a weak heart are sometimes sufficient to produce fatal shock. For 
these reasons the dental practitioner should never permit himself to oper- 
ate upon such individuals without the knowledge and co-operation of the 
patient's family physician. Such an association is a safeguard, in case of a 
serious or fatal termination of the operation, against unjust criticism or a 
suit for supposed malpractice. 

Whenever a tooth has to be extracted for a person suffering from any 
organic heart affection, it becomes necessary to administer cardiac stim- 
ulants, such as whiskey or brandy, aromatic spirit of ammonia, digitalis, 
strychnine, or a one per cent, solution of nitroglycerin. To obtain the 
best results, some one of these agents should be prescribed an hour or two 
before the contemplated operation. 

The operator who is thoroughly prepared for all emergencies will have 
a hypodermic syringe charged with a tablet containing one-fiftieth of a 
grain of digitalis or one-fiftieth of a grain of strychnine sulphate dissolved 
in one drachm of whiskey or brandy, or with the following combination 
(also put up in tablet form by Nelson, Baker & Co., of Detroit, Mich.). 

R Digitoxin, gr. ^ ', 
Nitroglycerin, gr. ^ ; 
Strychnine sulph., gr. T fc$. 
Dissolve in one drachm of distilled water. 

This combination is an exceedingly efficient remedy in cases of threat- 
ened heart failure, shock, or collapse, and should find a place in all emer- 
gency outfits. 

IV. Epilepsy. — Individuals who are so unfortunate as to be the sub- 
jects of epilepsy may be prepared for the operation by the administration- 
of large doses of potassium bromide, which will in many cases, for the 
immediate time at least, prevent or mitigate the severity of an attack. 
Nitrite of amyl, if applied during the convulsion, will sometimes cut the 
attack short. The nervous condition of these poor unfortunates is such 
that anxiety, fear, or the shock of an operation is prone to bring on an 
attack ; it is therefore unwise for the dentist to undertake the extraction of 
a tooth without the presence of the family physician or some other medical 
adviser. In case an attack comes on, all that can be done is to place the 
patient in the recumbent position, protect him against injury during the 
paroxysm, and prevent the laceration of the tongue and other soft tissues 
of the mouth from the spasmodic closing of the jaws. This may be ac- 



EXTRACTION OF TEETH. 599 

complished by placing a piece of soft rubber between the teeth, or a roll 
of bandage or other such material. 

V. Hemorrhagic Diathesis. — The hemorrhagic diathesis is due to 
deficient muscular tone in the coats of the blood- vessels, and to a lack of 
a normal coagulability of the blood. This diathesis may be hereditary or 
acquired, and it usually first shows itself at about the period of second 
dentition. It is a condition which often causes great anxiety and alarm to 
the operator, the patient, and the friends, as many cases of fatal hemorrhage 
following tooth-extraction in these individuals have been recorded. When 
the operator is aware of the diathesis he can usually, by appropriate treat- 
ment instituted a few days before the contemplated operation, control the 
tendency to hemorrhage by improving the tone or contractility of the 
blood-vessels and restoring the normal coagulability of the blood. 

A pill containing from ten to twenty grains of gallic acid and one grain 
of opium may be administered after each meal for three days, or the fluid 
extract of ergot may be given in doses of from twenty drops to one flui- 
drachm every two to four hours on the day previous to the operation. 
Ergot, however, must not be administered to pregnant females, on account of 
the danger of producing an abortion. 

VI. Pregnancy. — Women who are performing the functions of men- 
struation, gestation, or lactation should as far as possible be shielded from 
all operations. 

During the period of menstruation most women are in a peculiarly 
nervous condition, and much more susceptible to irritation and shock than 
at other periods. Vicarious menstruation from the alveolus of a recently 
extracted tooth has also been recorded. 

Many cases of premature labor have been placed on record as the result 
of shock from the extraction of a tooth, while congenital deformities and 
monstrosities have been charged to the same cause. A very slight nervous 
or mental shock is sufficient in some women to produce premature labor, 
while in others even a severe shock makes no impression. It is safer, 
however, under all circumstances requiring operation upon pregnant 
women to administer a general anaesthetic, and thus prevent the shock 
which would be likely to occur from the operation. 

During lactation mental anxiety, nervous irritation, and shock are 
liable, through some peculiar action of the nervous system, so to change 
the character of the lacteal fluid as to make it unfit for the nourishment of 
the infant, and in some cases to render it absolutely poisonous. Carpenter * 
records a case of this character in which immediate death of the child 
followed the taking of the breast of a nursing mother who had suffered 
great mental agitation. These occurrences have been explained in part 
by the discovery of Dr. Victor C. Vaughn, of Michigan University, who 
found that under certain fermentative changes a poisonous ptomaine, which 
he has termed tyrotoxicon, is formed in milk and cheese, and also in ice- 
cream. 

* Physiology, 1862, p. 742. 



600 



OPERATIVE DENTISTRY. 



INSTRUMENTS USED IN THE OPERATION OF EXTRACTING. 

An examination of the mouth and of the tooth to be removed should 
always be made before any steps are taken in the operation. For this 
purpose a mouth-mirror (Fig. 660) and a curved probe or explorer are 
necessary. 

Fig. 660. 



Mouth-mirror. 



Gum-lancets (Fig. 661) are employed in some cases to dissect the gum 
from around the cervix of the tooth prior to the adjustment of the extract- 
ing instrument. These cases are represented by the third molars, teeth 
which stand alone, and roots which are buried more or less completely 



Fig. 661. 



by overlying gum-tissue. In all other cases the use of the gum-lancet is 
rarely indicated, provided the beaks of the forceps are made sharp, so 
that they will cut their way through the margin of the gum as the in- 
strument is pushed towards the alveolar border. 

Fig. 662. 




Curved scissors (Fig. 662) are also necessary to a complete extracting 
outfit, and should be at hand for severing any portion of gum -tissue that 
might be found adherent to the cervix of the tooth. 



EXTRACTION OF TEETH. 



601 



Mouth-props and gags (Figs. 663 and 664) should be employed when a 
general anaesthetic is administered, the object being to obviate the neces- 
sity of having to open the mouth forcibly before the tooth can be reached, 
and to conserve valuable time, which is an exceedingly important con- 
sideration when nitrous oxide gas is used. (See also those on page 592.) 



Fig. 663. 



Fig. 664. 





Mouth-prop. Maso: 

The jaws of the Mason gag should be covered with rubber tubing, to 
prevent them from slipping or causing injury to the teeth. The jaws of 
the gag are separated by turning the milled nut downward. The curve 
of the jaws of the instrument is such that the handles extend backward 



Fig. 665. 




Warren's screw-gag. 

under the lobe of the ear, and are therefore entirely out of the way of the 
operator. 

In adjusting the gag, its jaws should be placed between the molar teeth 
upon the side of the mouth opposite to that where the operation is to be 
performed. 

The screw-gag (Fig. 665) is an exceedingly useful instrument for opening 

Fig. 666. 




forceps. 



or extending the jaws in cases of trismus caused by inflammation and 
swelling. Its application needs no explanation. 

A laryngeal forceps (Fig. 666) is also a necessary part of a complete 
extraction outfit. In case a tooth or a fragment of one should fall into 



602 



OPERATIVE DENTISTRY. 



the fauces beyond the reach of the finger, this instrument would be most 
valuable for its removal. 

The instruments which are employed for the extraction of teeth are 
the turnkey, forceps, and elevators. 

Turnkey. — The turnkey, which for many years was the only instrument 
employed in the extraction of teeth, has at the present time been almost 
entirely discarded. It is, however, a very serviceable instrument in certain 

cases where the crown of a molar 
Fig. 667. j^g fo een broken away by caries 

or accident to a point beneath the 
gum, upon the buccal or lingual 
side only, while the remaining 
portion is strong. Such cases offer 
great difficulties to their extrac- 
tion with the forceps, which either 
slip off or carry away the remain- 
ing portion of the crown, while 
it is often impossible to remove 
them with an elevator. The ap- 
plication of the turnkey (Fig. 667) 
to such teeth converts a difficult 
operation into a simple one. This is accomplished by placing the fulcrum 
upon the gum upon the side of the tooth which has been broken away, 
and the claw upon the opposite side of the tooth at the margin of the gum. 
This permits a proper direction of the force applied, and admits of an easy 
and natural removal of the tooth. 

Forceps. — In these days of aseptic surgery all forceps should be made 
in such a manner that they may be taken apart, as this gives a better 
opportunity for thorough sterilization. Fig. 668 shows an instrument of 
this character, the joint of which is very simple in construction, strong, 
and easily cleansed. 




Turnkey. 




Aseptic forceps. 



The beaks of the forceps should be of such shape as to fit as large a sur- 
face as possible of the cervix of the tooth for which they are constructed, 
without pressing too hard upon the cervix or the crown. If the pressure 
comes too hard upon the crown, it is liable to be crushed ; while if the 



EXTRACTION OF TEETH. 



603 



curve of the beaks is so great that the terminal edges grip the cervix only, 
there is danger of fracturing the tooth at this point. This quite often hap- 
pens with the use of lower molar forceps that are improperly constructed. 
The terminal edges of the beaks should be made sharp, so that when they 
are crowded against the cervical border of the gum they will cut their 
way, and thus avoid the necessity of using the gum-lancet. 

The handles of all forceps should be serrated in such a manner that 
when gripped by the hand they will not slip. This is very imx3ortant, for 
if any considerable pressure is placed upon the handles to keep them from 
slipping, there is danger of crushing the crown or cutting it off. 

The curves of the beaks and the handles must be of such form as to 
permit a proper adjustment of the beaks to the teeth to be extracted, while 
the handles should not impinge upon the anterior teeth of the opposite 
jaw, and should allow the force which is applied to be made in a direct 
line with the long axis of the tooth, or, in other words, in a line with the 
general direction of the roots. 

Elevators. — These instruments are devised for the extraction of roots 
which are too frail to withstand the grip of the forceps or the pressure of 




the turnkey. In app lying these instruments the grooved face is adjusted 
to the surface of the tooth, and the blade carried downward to the alveolar 
process. Force is then exerted in a direction to lift the tooth from the 
alveolus. Fig. 669 shows several forms of elevators, all of which are 
useful, and should be found in every complete extracting outfit. 

Fig. 670. 




Dental screw. 



The dental screw (Fig. 670) is also a valuable instrument for tne 
removal of very frail roots in which caries has followed the pulp-canal 
and converted the root into a mere shell. This instrument is applied by 
screwing it into the cavity in the root until the thread takes a firm hold 
upon the dentin, when the root is easily lifted from its alveolus. 



604 



OPERATIVE DENTISTRY. 



THE SELECTION OF THE PROPER INSTRUMENTS FOR THE EXTRACTION 
OF THE VARIOUS CLASSES OF TEETH, THEIR PROPER ADJUSTMENT, 
AND THE KIND AND DIRECTION OF THE FORCE APPLIED. 

The teeth, from the stand-point of their proper extraction, may be 
divided into seven classes, according to the number and the anatomic form 
of their roots. 

The first class includes the superior central and lateral incisors, which 
have single, cone-shaped roots. 

The second class embraces the inferior central and lateral incisors, 
which have single, considerably flattened, cone-shaped roots. 

The third class comprises the superior and inferior cuspids, which 
have single, very long, slightly flattened, cone-shaped roots. 

The fourth class includes the superior and inferior bicuspids, which 
have single, sometimes bifurcated, flattened, cone-shaped roots. 

The fifth class comprises the superior first and second molars, which 
have three cone-shaped roots, — two buccal and one lingual. 

The sixth class embraces the inferior first and second molars, with two 
flattened, cone-shaped roots, — one mesial and one distal. 

The seventh class in eludes' the superior and inferior third molars, 
which may have either a single cone-shaped root that curves backward or 
multiple roots. 

Fig. 671 shows the relation of the teeth to the alveolar process, and 
Fig. 672 shows the form and number of the roots of the teeth and their 
deeper relations to the alveolar processes. 

First Class. — In the extraction of teeth of ike first class, the operator 
should stand upon the right side of the patient, who is seated in the 
operating-chair with the head thrown well back and supported between 
the chest and the left arm of the operator, and the lips shielded from 
injury by the fingers of his left hand. The forceps selected for the opera- 
tion should be straight, as shown in Figs. 673 and 674. The instrument 
shown in Fig. 673 is intended for the extraction of the superior central 

Fig. 673. 




Superior central incisor forceps. 

incisors, but it is equally adapted for the extraction of the superior cuspids. 
The forceps is adjusted to the tooth by grasping the handles loosely with 



control of the opening and closing of the jaws of the instrument, and 
permits the regulation of the force applied in grasping the tooth, which is 
of considerable importance in extracting a tooth much weakened by caries. 
The beaks of the forceps are then crowded well beyond the cervix of the 





4&m 






EXTRACTION OF TEETH. 



605 



tooth, and in so doing cut their way to the alveolar border, loosening the 
attachment of the gum. In applying the force, the tooth should be gripped 
with sufficient firmness to prevent the forceps from slipping, and then 
rotated in a mesial or distal direction, when the attachments of the root 
with its alveolus will be broken up and the tooth removed. Should 
rotation fail to dislodge the tooth, a forward and backward movement may 
be given to the forceps, combined with rotation. 

Fig. 674. 




Superior lateral incisor forceps. 

Fig. 674 shows the usual form of the forceps employed for the extraction 
of the superior lateral incisors. The adjustment of the instrument and 
the application of force are the same as for the extraction of the superior 
central incisors. 

Second Class. — In extracting teeth of the second class, the operator 
should stand upon the right side of and a little behind the patient, whose 

Fig. 675. 




Inferior incisor forceps, full curve. 

lower jaw is supported with his left hand, and the lips shielded with 
the fingers of the same hand. The forceps shown in Figs. 675 and 676 are 
most admirably adapted for the removal of the inferior central and lateral 

Fig. 676. 




5 



Inferior incisor forceps, narrow beaks, full curve. 



incisors, while the hawk-bill forceps shown in Fig. 677, and the half-curved, 
narrow-beak forceps shown in Fig. 678, are useful in removing very narrow 
inferior central incisors and other inferior teeth with single roots which, 
by reason of an irregularity in their position, prevent the application of 



606 



OPERATIVE DEMTISTRY. 



the broader- beaked instruments ordinarily used for their extraction. The 
direction of the force which should be applied in the removal of these 

Fig. 677. 




Inferior incisor forceps, hawk-bill. 



Fig. 678. 




Inferior incisor forceps, half curve. 

teeth is forward and backward, to break up their attachments to the alveo- 
lus, and in an upward direction to lift them out. 

Third Class. — The positions of the patient and the operator and the 
means of supporting the head and protecting the lips are the same as 
described for the first class. The forceps best adapted to the extraction of 

Fig. 679. 




Superior cuspid forceps. 
Fig. 680. 




Superior cuspid and bicuspid forceps. 

the superior cuspids are those shown in Figs. 679, 680, and 681. Inasmuch 
as these teeth have the longest roots and are the most firmly fixed in their 
alveoli of all the teeth, it requires more skill and strength to extract them 
than any other teeth in the mouth, and consequently the instruments 



EXTRACTION OF TEETH. 



607 



used for this purpose must be very strong. In adjusting the forceps, 
the beaks should be forced upward and beyond the cervix as far as the 
border of the alveolus, the tooth firmly gripped, and force applied by a 
combined rotary, forward, and backward movement. The attachments of 
the tooth are thus broken up, and it is removed from its alveolus. 

The position of the patient for the extraction of the inferior cuspids 
should be as nearly upright as possible, with the chin well down upon the 
chest, while the position of the operator should be upon the right side and 

Fig. 681. 




Superior cuspid and bicuspid forceps. 



Fig. 082. 




Inferior cuspid and bicuspid forceps. 
Fig. 683. 




Inferior cuspid and bicuspid forceps, full curve. 

slightly behind the patient. The chair should be low enough to give 
him full opportunity to apply force in an upward direction, while at the 
same time it is applied in a forward and backward direction. The roots 
of these teeth are so much flattened laterally that rotation cannot be suc- 
cessfully employed. The forceps best adapted for the extraction of these 
teeth are shown in Figs. 682 and 683. 

Fourth Class. — The forceps which are best adapted for the extraction 
of the superior bicuspids are the same as those used for the removal of 
the superior cuspids. 

The positions of the patient and the operator, the support of the head, 
and the protection of the lips are the same as described for the removal of 



608 



OPERATIVE DENTISTRY. 



teeth of the first class. The instrument is adjusted by grasping the tooth 
at the cervix and crowding the beaks upward to the border of the alveolus, 
then firmly gripping the handles of the forceps and applying force for 
extraction in a combined forward, backward, and doionward direction. 



Fig. 684. 




Inferior bicuspid forceps, half curve. 

In extracting the inferior bicuspids the positions of the patient and 
operator, the position of the chair, and the protection of the lips are the 
same as described for the extraction of the inferior cuspids. The instru- 



Fig. 685. 




Inferior bicuspid forceps, full curve. 

ments best adapted for the extraction of these teeth are shown in Figs. 684 
and 685. The application of force should be in a combined forward, back- 
ward, and upward direction. 

Fifth Class. — The superior first and second molars, by reason of the 
number and form of their roots, often require considerable strength to 
dislodge them from their alveoli. The beaks of the forceps which are used 
for the extraction of these teeth require to be especially made to conform 
to the shape of the teeth at the cervix. The outer or buccal beak of the 
forceps is constructed with a projecting point in the centre, which fits 
into the sulcus formed by the bifurcation of the buccal roots, while the 
inner beak is made plain, to fit the convexity of the lingual surface of the 
lingual (palatal) root. These instruments are usually made in pairs, right 
and left, to suit the form of the teeth upon opposite sides of the mouth. 
The jaws and handles should be so curved as to make it possible to grasp 
these teeth and not have the handles come in contact with the corner of 
the mouth or the lips. Fig. 686 shows the form of these forceps. An- 
other form of forceps is that shown in Fig. 687. These instruments are 
bayonet-shaped, and have the beaks like those just described, one adapted 
for the teeth of the right side, the other for the left. The bayonet form 
given to these instruments makes them very valuable for the extraction 
of these teeth when the oral commissure is very small. 



EXTRACTION OF TEETH. 609 

In adjusting either of these instruments to the tooth the beaks are 
made to grasp the tooth at the cervix, the pointed beak being inserted 
between the buccal roots, and the instrument forced upward to the 
border of the alveolus. The handles are then firmly gripped, and the 





Right. Left. Right. Left. 

Superior first and second molar forceps. (Dr. Superior first and second molar forceps (bayonet 

Harris.) shape). 

tooth rocked by a backward and forward movement until it is loosened in 
its alveoli, when force may be applied in a downward direction, and the 
tooth dislodged. 

Sixth Class. — The inferior first and second molars have but two roots, 
and do not, therefore, as a rule, require so much force to extract them as do 




Inferior first and second molar forceps (universal), either side. (Dr. Harris.) 



the superior molars. The beaks of the forceps which are used for the ex- 
traction of these teeth are each made with a projecting point which fits 



610 



OPERATIVE DENTISTRY. 



into the buccal and lingual sulci formed by the bifurcation of the root. 
The jaws and handles of the forceps are also curved in such a manner as 
to permit the tooth to be grasped while the handles remain clear of 
the lips and of the corner of the mouth. Fig. 688 shows an instrument 

Fig. 689. 




Inferior right first and second molar forceps. 
Fig. 690. 




Inferior left first and second molar forceps. 



Fig. 691. 




Inferior universal first and second molar forceps. (Dr. Hutchinson.) 
Fig. 692. 




Inferior universal cow-horn forceps, first and second molars. 

which is adapted for use upon either side of the mouth, while in Figs. 
689 and 690 are seen forceps made in right and left forms. 

Fig. 691 shows another form of universal lower molar forceps, the 
invention of Dr. Hutchinson, while Fig. 692 illustrates a universal cow- 
horn lower molar forceps. These are also made for the right and left sides 
(Figs. 693 and 694). 



EXTRACTION OF TEETH. 611 

The position of the patient, that of the operator, and the method of 
protecting the lips are the same as in the extraction of the inferior 
cuspids and bicuspids. 

Fig. 693. 




Inferior left first and second molar, cow-horn forceps. 

In adjusting the forceps care must be taken to see that the points of the 
beaks are inserted into the buccal and lingual sulci formed by the bifurcation 
of the roots. The application of force should be a forward and backward 

Fig. 694. 




Inferior right first and second molar, cow-horn forceps. 

rocking movement until the tooth is loosened in its alveolus, when the 
tooth should be removed by traction upward. 

Seventh Class. — The superior third molars, by reason of their position 
and the usual backward curvature of their roots, are often very difficult to 
extract. When the root, however, is straight, their extraction is a very 
simple matter by the use of bayonet-shaped forceps having simple beaks 
made to fit the convexity of the root upon the buccal and lingual surfaces. 
Fig. 695 shows such an instrument designed for use upon either the right 

Fig. 695. 




Bayonet-shaped superior third molar forceps (universal). 

or the left side of the mouth. The positions of the patient and the 
operator and the application of force are the same as for the extraction of 
the other superior molar teeth. Sometimes these teeth are large and have 
bifurcated roots. Under such circumstances the ordinary superior molar 
forceps should be employed for their extraction. 



612 



OPERATIVE DENTISTRY. 



When the roots of these teeth curve backward the ordinary forceps 
used for the extraction of the third molars will not dislodge them. Special 
forceps are then called into use. To meet these requirements the late Dr. 
Physick invented the forceps shown in Fig. 696. The jaws of this instru- 
ment represent two inclined planes looking towards each other. The in- 
strument is designed to act as a double wedge when placed between two 

Fig. 696. 




Superior third molar forceps. (Dr. Physick.) 

resisting bodies and force is applied by closing the handles. In the ex- 
traction of a superior third molar the jaws of the forceps are opened and 
the edges placed between the approximating surfaces of the second and 
third molars. The handles of the forceps are then closed and depressed, 
or rather carried towards the morsal surfaces of the superior teeth : the 

Fig. 697. 




Superior third molar, extracting, separating, and excising forceps. (Dr. Stellwagen.) 

double wedge of the jaws thus starts the tooth from its alveolus and the 
depression of the handles carries the crown backward, dislodging it from 
its alveolus. Tigs. 697 and 698 represent instruments designed by Dr. 
Stellwagen for the combined purpose of extracting superior and inferior 
third molars and excising and separating roots. The principle involved 
in their application is the same as in the Physick forceps. 

Fig. 698. 




Inferior third molar, extracting, separating, and excising forceps. (Dr. Stellwagen.) 



The inferior third molars have usually single roots which curve back- 
ward, but occasionally the roots are multiple. Under these circumstances 
they can usually be extracted with the forceps shown in Fig. 699, but 



EXTRACTION OF TEETH. 



613 



when the root is curved it becomes necessary to employ the Physick 
or Stellwagen forceps. The instrument is applied as for the removal of 
the superior third molars, and the handles are closed and depressed. This 
starts the tooth from its alveolus, tips it backward, and dislodges it. Care 
must always be exercised in the use of these forceps not to injure the tooth 
in front which acts as the fulcrum. If these instruments are carelessly 

Fig. 699. 




Inferior third molar forceps. 

handled there is danger of fracturing the enamel, thus preparing the way 

for the establishment of caries in the injured tooth. 

Extraction of the Roots of Teeth. — For the extraction of the roots 

of teeth specially devised forceps are generally employed ; these have 

usually thin, narrow beaks that can be insinuated between the gum and 

the root. 

Fig. 700. 



g^ggjSgS^ga 




Screw-forceps. (Dr. C. H. Dub: 



For the extraction of the roots of the six superior anterior teeth which 
are so decayed as to present thin, frail walls the Dubs serew-forceps (Fig. 
700) and the Hullihen screw-forceps (Fig. 701) are the best. These in- 
struments combine the dental screw with the narrow-beaked forceps. 



Fig. 701. 




Screw-forceps 



P. Hullihen.) 



To adjust the instrument to the root the conical screw is first set into 
the pulp cavity. If much softened dentin is present this should first be 
removed and the screw so set that it takes hold upon the sound dentin. 
The socket between the jaws of the forceps is then p laced over the shaft of 



614 



OPERATIVE DENTISTRY. 



the screw, and the beaks of the instrument are insinuated between the gum 
and the root and carried down to the alveolus. The handles are then 
gripped with just sufficient force to prevent the instrument from slipping, 
and the root is rotated to the right, — the direction in which the screw is 
set, — and the tooth is dislodged from its alveolus. 



Fig. 702. 




Superior anterior root forceps. 



Fig. 703. 




Superior bicuspid and molar root forceps, half-curve. 
Fig. 704. 




Superior bicuspid and molar root forceps, bayonet shape. (Dr. B. F. Arrington.) 
Fig. 705. 




Superior root forceps, bayonet shape. (Dr. Ambler Tees.) 

Fig. 702 represents a straight root forceps designed for the extraction 
of the roots of the six superior anterior teeth, which can be used in all 
cases where the root is not so badly decayed as to be liable to crush under 
the pressure necessary to keep the instrument from slipping during the 
extraction. 

For the extraction of the superior bicuspids, the half-curved forceps 
represented in Fig. 703 will be found most admirable instruments. 



EXTRACTION OF TEETH. 



615 



For the extraction of the roots of the superior molars there is no better 
instrument than the bayonet-shaped root forceps shown in Figs. 704 and 
705. 

Great care should be exercised in the extraction of the roots of the su- 
perior bicuspids and molars not to force them upward into the antrum of 
Highmore, as under such circumstances an extended surgical operation 
becomes necessary for their removal, involving the exsection of i» con- 
siderable portion of the floor of the sinus. 




Inferior incisor, cuspid, and bicuspid root forceps, full curve. 

For the extraction of the roots of the six inferior anterior teeth and 
the bicuspids, the full-curved lower-root forceps shown in Figs. 706 and 

Fig. 707. 




Inferior root forceps, full curve. (Dr. Ambler Tees.) 

707 will be found most useful. The points of the beaks in the "Tees" 
forceps are made thin so that it is possible to insinuate them between the 
root and the gum. 

Fig. 708. 




Superior alveolar root forceps, bayonet shape, with beaks of Dr. Kell's pattern. 



In the extraction of roots in the superior jaw that are buried in the 
tissues, the "alveolar" forceps shown in Fig. 708 is most admirably 
adapted. When using this instrument the gum should be incised upon the 
labial and lingual surfaces in a line corresponding to the long axis of the 
root, and the edges of the gum lifted from the alveolar process upon both 



616 



OPERATIVE DENTISTRY. 



sides of the incisions. The beaks of the forceps may now be insinuated 
between the gum and the alveolar process, and by a quick, firm pressure 
upon the handles, the alveolar process is cut through and the root removed. 

Fig. 




Fi« 



Deciduous inferior universal forceps. (Dr, M. H. Cryer.) 

In the extraction of the roots of lower molars the forceps shown in 
r;. 709 is most admirably adapted, the beaks being long, thin, and narrow. 

Fig. 710. 




Inferior alveolar root forceps. (Dr. J. D. Thomas.) 

The " alveolar" forceps of Dr. Thomas shown in Fig. 710 is a very valu- 
able instrument for removing such roots as are broken off below the gum. 

Fig. 711. 




Deciduous superior anterior and root forceps. 

The forceps which are used for the extraction of the deciduous teeth 
should be much smaller and lighter than those employed for the extraction 

Fig. 712. 




Deciduous superior molar forceps. 

of the permanent teeth. Three pairs are sufficient for all purposes. Fig. 
711 is for the extraction of the six superior anterior teeth and roots, and 



« 9 f $ 



" «■ <L 4T 




Fig. 717.— After Dr. M. H. Cryer. 




Fig. 718.— After Dr. M. H. Over. 




Fig. 719.— After Dr. M. II. Over. 




Fig. 720.— After Dr. M. H. Over. 




Fig. 721.— After Dr. M. H. Oyer. 




Fig. 722.— Skiagraph showing misplaced superior cuspid tooth. 



EXTRACTION OF TEETH. 



617 



Fig. 712 for the superior molars. Fig. 713 is used for the extraction of the 
six inferior anterior teeth and for the inferior molars. The "universal" 
root forceps of Dr. M. H. Oyer (Fig. 714) are also admirable instruments 
for the extraction of children's teeth. 

Fig. 713. 




Deciduous inferior anterior and molar forceps. 
Fig. 714. 




Deciduous and superior universal root forceps. (Dr. M. H. Cryer.) 



DIFFICULTIES, COMPLICATIONS, AND ACCIDENTS. 

Anomalous Teeth. — The accompanying illustrations (Figs. 715 and 
716) represent some of the more common deformities of the teeth. Figs. 
717, 718, 719, 720, and 721, which are kindly loaned to the writer by 
Dr. M. H. Cryer, show some of the more common malpositions of the 
teeth which complicate the operation of extraction, and often render it 
extremely difficult and sometimes hazardous. Fig. 722 is a skiagraph 
showing a misplaced superior cuspid. 

The cases which present the greatest difficulties are the teeth having 
sharply curved roots, hypercementosed roots, and teeth which are mis- 
placed and impacted in the jaws, particularly impacted third molars. 

Teeth having curved or hypercementosed roots offer great resistance to 
the force applied for their extraction. In the former the curved end of 
the root is often fractured and left in its alveolus, while in the latter the 
alveolar process is usually fractured, the external plate giving way on a 
line with the alveoli, in the endeavor to remove the tooth. 

The former accident is, however, of small moment, and the fractured 
portion of the root may be allowed to remain, as it very rarely causes any 
serious after- trouble. 

The fracture of the alveolar plate is more serious, and if neglected or 
improperly treated may result in necrosis. If, however, the fractured 
parts are brought into close apposition by squeezing them together with 
the thumb and index finger, and the alveolus frequently irrigated with 
antiseptic solutions, union will take place and little or no inflammation or 
soreness will result ; but if, on the other hand, the fractured parts are 
allowed to remain separated, and no attention is paid to antiseptic treat- 
ment, osteitis and necrosis are liable to occur. 



618 



OPERATIVE DENTISTRY. 



Fig. 723. 



The most difficult teeth to extract are the impacted third molars, which 
lie more or less horizontally in the jaw and impinge upon the distal sur- 
face of the crown or the root of the second 
molar, as shown in Fig. 723. This condition 
of impaction occurs most often in the lower 
jaw. When the crown of the inferior third 
molar is tilted forward so that it impinges upon 
the distal surface of the second molar near the 
cervix or lower down upon the root, further 
progress in the eruption of the third molar is 
arrested, and irritation and inflammation are 
liable to supervene, making it necessary to ex- 
tract the tooth. In order to accomplish the 
removal of the impacted tooth, it becomes neces- 
sary to cut away with corundum disks a con- 
siderable portion of the mesial cusps of the 
third molar. After this has been done the tooth may be grasped with 
the forceps shown in Fig. 724 and the tooth dislodged from its alveolus. 
Or it may be dislodged with the Physick or Stellwagen " wisdom-tooth" 
forceps (Fig. 725). 

Fig. 724. 




Inferior left second and third 
molars as they were located in 
the jaw. 




If, however, the third molar has not erupted or only shows a very small 
portion of the crown through the gum, and the tooth occupies a hori- 
zontal position in the jaw, two courses only can be suggested for its 
removal. 

Fig. 725. 




Physick forceps. 



The first is to remove the second molar, as this makes it possible to 
reach the third molar and extract it. 

The second is to dissect the gum from over the impacted tooth, chisel 
or bur away the bone overlying it, and then lift it from its bed with an 
elevator or Physick forceps. 

Operations of this magnitude should, of course, be made under a gen- 
eral anaesthetic, preferably ether, as nitrous oxide anaesthesia would not 
last long enough to permit the operation to be performed painlessly. 



EXTRACTION OF TEETH. 619 

Other teeth than the third molars are sometimes impacted in the jaws, 
and require surgical operations for their removal. Those which are most 
commonly misplaced are the superior cuspids (Fig. 721), laterals, and bi- 
cuspids, and the inferior bicuspids and cuspids, their relative frequency, 
according to the experience of the writer, being in the order named. A 
good general rule to be followed in operations for the removal of impacted 
teeth is never to sacrifice any other tooth if it can possibly be avoided. 

Fractures of the Teeth. — In the extraction of teeth that are badly 
decayed, and in those which by reason of abnormalities in form or position 
present great difficulties in their removal, fractures of the crown are very 
liable to occur. Under such circumstances the roots should be immediately 
removed with instruments suited to the individual case. Sometimes, how- 
ever, the fracture occurs at the alveolar margin or even lower down, 
making the removal of the root an exceedingly difficult task, except by the 
subalveolar method previously described. For this reason the alveolar 
forceps shown in Figs. 708 and 710 should be found in every complete 
extracting-case. If the tooth which has been fractured has double or 
multiple roots, it often becomes necessary to divide them with Stellwagen 
excising forceps, and extract each root separately. 

When a tooth is extracted, fractured or crushed, great care should be 
taken to prevent the tooth or the fragments slipping from the jaws of the 
forceps and falling into the fauces, and becoming arrested at the entrance 
of the larynx by engaging in the rima glottidis, or, passing downward, 
becoming lodged in the trachea or one of the bronchi (more often the 
right), thus preventing or impeding the admission of air to the lungs and 
causing spasmodic coughing, dyspnoea, and the more serious symptoms of 
asphyxia. 

Whenever a foreign substance falls into the fauces the body of the 
patient should immediately be thrown forward, and the index-finger passed 
into the mouth and swept around the fauces, in the hope of removing it. 
Failing in this, the patient's body should be inverted, and while in this 
position the back vigorously slapped with the flat of the hand. If, how- 
ever, the foreign body has passed beyond the reach of the fingers, the 
laryngeal forceps may be employed to reach it, and this may often be done 
if it has not passed beyond the rima glottidis. If the foreign body has en- 
tered the trachea or become lodged in a bronchus, an immediate trache- 
otomy is the only means of relief. Cases of this character may prove imme- 
diately fatal ; while, upon the other hand, if the fragment of tooth is small, 
and has passed into a bronchus, it may give rise to no immediate symp- 
toms, but later the patient may be seized with violent fits of coughing, 
dyspnoea, bloody expectoration, and finally collapse of the lung. Miller 
records a case of suppuration and gangrene of the lung due to the presence 
of a fragment of a decayed tooth. 

Impaction of a tooth or a fragment of a tooth or other foreign body in 
the oesophagus or the pyloric orifice of the stomach sometimes occurs, and 
may give rise in the former to symptoms of dysphagia, and in the latter to 
gastric dilatation and ulceration. The treatment of these cases belongs to 
the domain of general surgery. 



620 OPERATIVE DENTISTRY. 

Fractures of the Alveolar Process. — Fractures of the alveolar pro- 
cess are frequently the result of the extraction of the teeth. This accident 
most often occurs in connection with the superior and inferior cuspids and 
the superior molars. 

Teeth which stand alone are the most liable to this accident, although 
it may occur in connection with the extraction of any tooth if the process 
is thin, or the operation is roughly or unskilfully performed, or the roots 
are malformed, abnormally large, or, as in the molars, widely spread. 

Sometimes the attachment of the alveolar process is so firm that the 
fractured part comes away with the tooth. This makes an ugly wound in 
the gum, which may require two or three stitches to bring it together. 

In the treatment of the other forms of fracture of the alveolar process 
the simple adjustment of the fractured parts to their normal position and 
the use of antiseptic solutions is usually all that is required. 

Osteitis. — Inflammation of the alveolar process is a frequent sequel of 
the extraction of a tooth in which the gums and process have been bruised 
and lacerated. This most frequently occurs in those cases where the tooth 
has been fractured some distance beneath the margin of the gum, and re- 
peated unsuccessful attempts have been made to remove it. 

The disease is attended with great pain, tenderness, and swelling of the 
surrounding tissues, suppuration, and sometimes sloughing of the soft tis- 
sues and death of the bone. 

The treatment consists in the free use of antiseptic and stimulating 
lotions, and anodynes to control the pain. 

Gangrene and Necrosis. — These conditions frequently follow the 
unskilful extraction of the teeth, and are the result of crushing the soft 
tissues in the one case, and of fractures, injuries which cut off the circula- 
tion, or inflammation in the other. The treatment consists in removing 
all dead or gangrenous soft tissue with scissors or knife, washing the parts 
with hydrogen dioxide to remove the pus, and following this with suitable 
antiseptic lotions. 

Necrosed bone should not be disturbed until separation has taken place 
between the dead and the living portions. Meddlesome treatment only 
aggravates the inflammatory process, and often causes an extension of the 
disease far beyond the limits which were previously involved. The only 
treatment to be recommended is that comprehended under the term anti- 
septic until the sequestrum has formed, when it should be immediately 
removed, and the parts assisted in the healing process by thorough cleanli- 
ness and the use of stimulating and antiseptic solutions. 

Hemorrhage. — Hemorrhage of a severe and continuous type often 
seriously complicates the operation of tooth extraction in those individuals 
who are subjects of the hemorrhagic diathesis, and quite a number of cases 
are on record in which the hemorrhage has proved fatal after every effort 
had been made to arrest it. 

Hemorrhage may be primary, recurrent, or secondary. 

Primary hemorrhage is that which occurs from the alveolus immediately 
after the tooth has been extracted, and usually does not continue for more 
than half an hour. Sometimes, however, the primary hemorrhage is pro- 



EXTRACTION OF TEETH. 621 

fuse, and calls for treatment for its control. The use of cold water or ice- 
water, or water as hot as can be borne in the mouth, to which a few drops 
of tincture of myrrh or aromatic sulphuric acid have been added, will gen- 
erally be sufficient to arrest it. 

Recurrent or secondary hemorrhage is that which follows a few hours after 
the primary hemorrhage has ceased. 

This form of hemorrhage usually comes on in the night following the 
day upon which the tooth was extracted, or following the sloughing of soft 
tissue whose vitality had been destroyed by the traumatism or by the 
application of escharotic styptics. 

Sometimes the hemorrhage seems to be confined to the artery which 
supplied the tooth, the blood welling up from the apex of the alveolus ; in 
other cases the whole inner surface of the alveolus seems to take part in 
the hemorrhage ; while in others it may be confined to the gum. In the 
more severe cases in which there is a marked history of the hemorrhagic 
diathesis, the blood is found to flow not only from the dental artery, but 
from the inner walls of the alveolus and the gums as well, the bleeding in 
some cases being so profuse that the patient may lose from a pint to a 
quart or more of blood in a few hours, causing great weakness and con- 
siderable alarm and anxiety upon the part of the patient and the friends. 

In examining the mouth in a case of secondary hemorrhage, care should 
be taken to locate the exact source of the bleeding, whether it is from the 
gum, the inner wall of the alveolus, or the dental artery. 

If the hemorrhage comes from the gum, the bleeding point may be 
compressed with the haemostatic forceps, or any little vessel picked up and 
torsion applied. If this does not arrest the bleeding, a compress may be 
made of warmed gutta-percha or modelling compound, pressed over the 
part, and when cooled removed, lined with lint or cotton, saturated with 
a solution of tannic acid in glycerol, and returned to the mouth, and com- 
pression made by closing the jaws upon the compress, and binding them 
together with a four-tailed bandage. When the hemorrhage is from the 
socket or the dental artery, the case should be treated by plugging the 
alveolus. This may be done by forming a plug to fit the alveolus from 
warmed wax or modelling compound, made in the form of a cone, a little 
longer and larger than the tooth which had been removed, and pressing it 
firmly into the alveolus. The large end of the plug should rise a little 
above the crowns of the adjacent teeth, so that when the jaws are closed 
pressure will be brought to bear upon the plug. When cooled it can be 
removed, the alveolus cleared of blood-clots and washed with ice-water 
charged with a suitable antiseptic, and the plug returned to the alve- 
olus after it has been rolled in tannic acid or dipped in the tannic acid 
and glycerol solution. The jaws should then be closed upon the plug and 
maintained in that position by the adjustment of the four-tailed bandage. 
• The writer considers this method very much better from the aseptic 
stand-point than the old method of packing the alveolus with cotton, lint, 
or strips of bandage, as the liability to septic infection and suppurative 
inflammation is greatly reduced. 

When the hemorrhage comes from the alveoli of several contiguous 



622 OPERATIVE DENTISTRY. 

teeth, each alveolus should be treated by the method described, and then 
all may be bound together, while they are in place, by another piece of 
warmed modelling compound pressed down over the exposed ends of the 
plugs and moulded to the gnms upon the buccal and lingual surfaces, and 
when nearly cooled the jaws may be closed upon it sufficiently to take an 
impression of the opposing teeth. 

After the mass has thoroughly cooled it may be removed altogether, the 
plugs treated as just described, and the whole returned to its place and 
retained in position by the closed jaws and the four-tailed bandage. 

If there is time to do so, and the facilities are at hand, a metal or vul- 
canite splint may be constructed from an impression taken of the parts. 
When this method is pursued, the alveoli should be plugged with modelling 
compound and the splint used to force the plugs into place and produce 
compression upon the gums. 

A few cases are on record in which, after arresting the hemorrhage 
from the alveolus, oozing of blood from the mucous surface of the gums 
occurred, as is sometimes seen in scorbutus and purpura hemorrhagica. 

In these cases it becomes necessary to secure compression over a con- 
siderable area of the gums, and this can best be accomplished by the metal 
splint just described. 

Before applying the splint it should be lined with cotton or lint, and 
saturated with a non-irritating styptic. The use of escharotic styptics, 
like the perchloride of iron, nitric acid, and chromic acid, should never 
be permitted, as they cause sloughing of the soft tissues and secondary 
hemorrhage, which is more difficult to control than the former condition, 
by reason of the greater surface involved as a result of the escharotic 
action of the remedy. 

After the compresses have been applied, the patient should be instructed 
to keep as quiet as possible, maintain the sitting posture, and avoid all hot 
fluids and stimulants. Liquid diet should be ordered, —milk, beef extracts, 
broths, and soups. 

In those cases in which there has been great loss of blood, stimulants 
may be administered and the body kept warm. The hot foot-bath is some- 
times serviceable in diverting the blood to the lower extremities and re- 
lieving arterial tension in the upper part of the body. 

To the constitutional remedies which have been mentioned as useful in 
controlling the tendency to hemorrhage in those persons having the 
hemorrhagic diathesis, — viz., gallic acid combined with opium, and the 
fluid extract of ergot, — the perchloride of iron may be added, — 

R Liq. ferri perchlor. , m. x ; 

Aq. destill., f|j. M. 
To be taken every two hours. 

Fatal syncope has been known to follow the extraction of a tooth in cases 
in which there was no functional or organic disease of the heart. 

Tomes calls attention to two such cases that have been placed on record. 
A similar case came under the knowledge of the writer, as occurring in 



EXTRACTION OF TEETH. 623 

the practice of a friend. In this case, however, there was fatty degenera- 
tion of the heart, as shown by the post-mortem examination. The patient 
was a lady about sixty years of age, and was apparently in good health. 
The dentist seated her in the chair preparatory to the operation, and 
turned to his case to select the instrument, when she fainted and could not 
be resuscitated, death occurring almost instantaneously. 



INDEX. 



Abbot on resorption of teeth, 76 
Abrasion, causes of, 371 

definition of, 368, 371 

treatment of, 372 
Abscess, dento-alveolar, see Dento-alveolar 



Acids and alkalies, influence of, on growth 

of bacteria, 90, 91 
Albuminoids and mouth bacteria in caries, 

151 
Alcohol, use of, in hypersensitive dentin, 

190 
Alexander's method of making gold inlays, 

347, 348 
Alloys, composition of, 314-319 

making of, 319, 320 
Allport's pyorrhoea alveolaris instruments, 

547 
Aluminum, use of, in alloys, 314, 315 
Alveolar abscess associated with deciduous 
teeth, 488 
chronic, 485 

treatment of, 486, 487 
Amalgam-carriers, 326 
Amalgam, definition of, 296 
fillings, finishing of, 330 
indications for use of, 321, 322 
-instruments, 326, 327 
manipulation of, 325-327 
nature and properties of, 298 
setting of, 298, 299 
watering of, 327 
Amalgams, annealing of, 309, 310 
color of, 312 
composition of, 296, 297 
conductivity of, 312, 313 
contraction and expansion of, 299-310 
flow of, 306 
mixing of, 323-325 
stability of, 310, 311 
washing of, 325 
Amelification, 39 
Ameloblasts, 32, 34, 35 



Ammonia, use of, in treating gold, 256, 

257 
Anaesthesia, Bon will's method, 216 
definition of, 578 
electro-cocaine, 207-211 
general, 586-594 

examination of patient for, 590, 

591 
Hewitt's method, 589, 590 
precautions against accidents, 591, 
592 
local, 578-586 

Letamendi's method, 580, 581 
-Richardson's method, 579, 580 
with chloretone, 584, 585 
with cocaine, 581-583 
with eucaine, 584 
with tropacocaine, 583, 584 
use of, in hypersensitive dentin, 187, 
214-216 
Anaesthetic, see Anaesthesia 
Anatomy, classification, and description 

of the teeth, 1 
Animal fungi (mycetozoa), 85 
Anomalous teeth, 617 
Anterior teeth, separation of, 175 
Antikamnia, use of, in pericementitis, 465 
Antimony, use of, in alloys, 314 
Approximal cavities, preparation of, 225- 

228, 230, 231 
Arkansas stones, use of, in formation of 

margins, 249 
Arkovy on action of arsenic upon dental 

pulp, 426, 427 
Arnott on local anaesthesia, 581 
Arsenic, physical effects of, on dental pulp 
424, 425 
use of, in devitalizing pulps, 423, 427- 
429 
Atropia sulphas, use of, in hypersensitive 

dentin, 188 
Attrition, causes of, 369, 370 
definition of, 368 
pathology of, 370 
treatment of, 370 



40 



626 



INDEX. 



Bacilli, classified, 86, 88, 89 
Bacillus, anthrax, 87 

buccalis maximus, 93, 97, 99 
Bacteria, action of antiseptics on, 169 
aerobic, 86 
aerogenic, 87 
anaerobic, 86 
chrornogenic, 87 
classification of, 86 
conditions necessary for growth of, 

154 
effect of, on integrity of dental tissues, 

101, 102 
functions of, 87 
in caries, 153 

influence of heat and moisture on, 91 
in mouth, 92, 148 
multiplication of, 89, 90, 98 
pathogenic, 87, 88, 92 

action of, 102 
saprogenic, 87, 101 
zymogenic, 87, 101 
Bacteriology, definition of, 83 
Balsam del deserto, use of, 489 
Barbed nerve-broaches, 430 
Batteries, electric, description of, 200, 201 
Bibulous paper, exclusion of moisture by, 

178, 179 
Bichloride of mercury as an antiseptic, 169 
use of, in implantation, 498, 500 
in transplantation, 495 
Bicuspids, cavities (compound) of, prepa- 
ration of, 231-233 
(simple) on approximal surfaces, 
preparation of, 227, 228 
on exposed surfaces, prepa- 
ration of, 220-225 
inferior, 15, 16 
superior, 12-15 
Bing's pluggers, 259 
Bismuth, use of, in alloys, 315 
Black on chronic pulpitis, 415 
on erosion, 366 

on pathology of pulp hyperemia, 381 
on resorption of teeth, 76 
on secondary dentin, 422 
on suppuration of pulp, 410 
Black's method of treating acute alveolar 
abscesses, 483, 484 
one-two-three mixture, 463 
Bleaching discolored teeth, 446-458 

cataphoric method, 455^58 
chlorine method, 451 
dioxide methods, 452-455 



Bleaching discolored teeth, sulphurous 
anhydride method, 455 
Truman method, 451, 452 
preparation of tooth for, 449, 450 
Blind abscesses, drainage of, 483 
Blood-serum therapy in poisoning from 

bacteria, 90 
Boll on nerve-endings in pulp, 44 
Boric acid, use of, in implantation, 499 
Brophy's band matrices, 284 
Bud fungi, description of, 85 
Bunge on analysis of proteids, 447 
Burnishers for finishing fillings, 288, 289 
Burs, plug-finishing, forms of, 189 



Cadmium, use of, in alloys, 315, 316 
Calcic deposits upon the teeth, 521 
Calcification, definition of, 34 
Calcoglobulin, 36, 44 
Calcospherites, 32, 35, 51 
Callahan's method of enlarging pulp- 
canals, 436 
Cannabis indica, use of, in hypersensitive 

dentin, 188 
Caoutchouc, separating teeth with, 177 
Carbohydrates, fermentation of, 101, 102 
groups of, 150 
in the mouth, 148 
Carbolic acid, use of, in devitalizing pulps, 
424 
in disinfecting cavities, 246 
in hypersensitive dentin, 190, 
191 
Caries, abnormal oral secretions as predis- 
ing cause of, 123, 124 
central, origin of, 140 
chemical theory of, 140-143 
constitutional predisposing causes of, 

124-131 
decalcification of, 156, 157 
definition of, 115 
diagnosis of, 163, 164 
diagnostic of inherited syphilis, 129, 

130 
electro-chemical theory of, 143, 144 
etiology of, 123 
excision of, 172, 173 
expansion of tubuli in, 157-160 
forms of, 140 
germ theory of, 144 
historic facts, 115, 116, 135-148 
humoral theory of, 136 
immunity in, 154, 155 
inflammatory theory of, 136-139 



627 



Caries, influence of continued fevers on, 130 
of exanthemata on, 130 
of inherited disease on, 129, 130 

irregularities as predisposing cause of, 
132, 133 

local predisposing causes of, 131-134 

of bone, 135 

of cementum, 60 

of dentin, 153 

penetration of, 160 

peripheric, origin and forms of, 140 

phenomena of, in dentin, 155, 156 

pigmentation of, 156, 157 

predisposing causes of, 123-134 

prevalence of, in present civilization, 
118, 119 

prognosis of, 164, 165 

prophylactic treatment of, 166, 170 

putrefaction theory of, 140 

silver nitrate in treatment of, 171, 172 

stages of, 161, 162 

structural defects as predisposing cause 
of, 131, 132 

susceptibility in, 154, 155 

symptoms of, 162, 163 

syphilis, hereditary, and, 129, 130 

tables relative to, 121, 122 

theories of, 136 

therapeutic treatment of, 171 

traumatic injuries as predisposing 
cause of, 132 

varieties of, 161 

worm theory of, 139, 140 
Carnivora, definition of, 1 
Caseation, definition of, 401 
Cataphoresis, definition of, 193 

resistance of tissues in, 211, 212 

substances used in, 196 
Cataphoric appliances, 456-458 

bleaching method, 455-458 
Cavities, classification of, 217, 218 

guarding of, with amalgam, 328, 329 

margins of, formation of, 248 

opening of, 235, 244 

preparation of, 212, 234, 235, 354 

removal of decay in, 244 

retentive shape of, 246-248 
Cementification, 35, 53 
Cementoblasts, 35 

Cement spatulas and mixing-slab, 338 
Cementum, 52 

caries of, 160 

histological composition of, 52 
Chappell's pluggers, 265 
Chloretone as a local anaesthetic, 584, 585 

in hypersensitive dentin, 188 



Chloretone in lining cavities, 332 
Chlorinated soda as a bleaching agent, 452 
Chlorine as a bleaching agent, 451 
Chloroform, use of, in hypersensitive den- 
tin, 216 
Chloro-percha, use of, in filling pulp-canals, 

442 
Cleansing teeth, instructing patients in, 

167 
Climatic influences predisposing to caries, 

126, 127 
Cloves, oil of, use of, in disinfecting cavi> 
ties, 246 
in hypersensitive dentin, 190 
Cocaine as a local anaesthetic, 581-586 
in cataphoresis, 194, 208, 212 
in hypersensitive dentin, 188 
in phagedenic pericementitis, 577 
poisoning, symptoms of, 585, 586 
treatment of, 586 
Cocci, 85, 86 

Conducting cords and tips, electric, 207 
Constitutional treatment of primary mor- 
bid dentition, 70, 71 
Copper amalgam, antiseptic action of, 313 
as a filling-material, 329, 330 
manipulation of, 317, 318 
preparation of, 316, 317 
electric conductivity of, 202 
use of, in alloys, 316 
Corundum wheels, forms of, 290 
Cotton, exclusion of moisture by, 178, 179 
filling pulp-canals with, 440 
separation of teeth with, 176 
sterilization of, 176 
Cushing's pyorrhoea alveolaris instru- 
ments, 548 
Cuspids, cavities in, compound, prepara- 
tion of, 229-231 
simple approximal, preparation 
of, 225-227 
exposed, preparation of, 218- 
220 
inferior, 11, 12 
superior, 9-11 
Custer's electric oven, 352 



Darby-Perry pluggers, 265 

Darby's capsicum and sinapin plasters, use 

of, in pericementitis, 464 
Decalcification in caries, 156, 157 
Decay, percentage of, in deciduous teeth, 
120 
in permanent teeth, 120 



628 



Deciduous teeth, 2, 24, 25, 73 

extraction of, indications for, 595, 

596 
exuviation of, 73, 74 
formula for, 2 
resorption of, 74, 75 
retention of, causes of, 74 
Dental groove, primary, 29 
secondary, 29 
ridge, 30 
tissues, calcification of, 34 

chemical composition of, 54 
histology of, 34 
Dentin, caries in, 155, 156 

chemical composition of, 42 
decalcification of, 244-246 
definition of, 41, 184 
discoloration of, 429, 430 
pathology of, 447-449 
globules, 47 

hypersensitiveness of, 184 
causes of, 184, 185 
treatment of, 186, 187, 214 
anaesthetic, 214-216 
chemical, 188-192 
palliative, 187, 188 
matrix of, 42 
papillae of, 30, 31 
Dentinal fibres, disorganization of, in 
caries, 159, 160 
fibrils, function of, 44 
sheaths, 44 
tubuli, 43 
tumors, 39 
Dentinification, theories of, 35, 48 
Dentition, 59 

primary, causes of irritation, 65, 66 
constitutional treatment of, 70, 71 
eruptive process of, 60-62 
local symptoms of, 69, 70 
morbid, 64 

complications arising from, 

67, 68 
treatment of, constitutional, 
70, 71 
local, 71 

gum-lancing, 71, 72 
mortality from, 68, 69 
periods of completed root forma- 
tion of, 64 
of eruption of, 59 
secondary, symptoms of, 79 
Dento-alveolar abscess, causes of, 474-476 
chronic, 479 
definition of, 474 
differential diagnosis of, 480 



Dento-alveolar abscess, location of, 477-479 
pathology of, 476, 477 
prognosis of, 480-482 
pus formation in, 477 
symptoms and diagnosis of, 479, 
*480 
treatment of, constitutional, 482 

local, 482-485 
varieties of, 476 
Denudation (erosion), definition of, 359 
De Trey's solila gold, 269 
Diapedesis (exudation), definition of, 398 
Dislocation of teeth, 501 
Disto-labial cavities, preparation of, 229 
Disto-lingual cavities, preparation of, 229, 

230 
Disto-morsal cavities, preparation of, 231 
Donaldson's bristles and pulp-canal 

cleansers, 435 
Dover's powder, use of, in pericementitis, 

465 
Dynamo-current controllers, 206 



Electric gold annealers, 271 

hot-air syringe, 190 

mouth-lamp, 111 
Electricity, generation of, 199, 200 

induced, classes of, 202 

transmission of, 202 

units of measurement in, 203, 204 

use of, in phagedenic pericementitis, 
577 
Electrolysis, anodal, 197, 198 

cathodal, 198, 199 
Elevators for extraction, 603 
Elliot's clamp and forceps, 182 
Enamel, calcification of, 39, 40 

caries of, 152, 153 

chemical composition of, 38 

-chisels, use of, in opening cavities, 
242-244, 249 

definition of, 36 

-globules, 41 

-organ, 30 

blood-supply of, 40 
invagination of. 31 

-prisms, 37 

transverse striations of, 37 
Endogenous spore formation, 98 
Engine-burs, use of, in opening cavities, 

241, 242, 249 
Epiderm, development of, 27 
Epithelial band, 30 

cells, 26 



INDEX. 



629 



Epithelial lamina, 30 

tissue, evolution of, 26 
Erosion of teeth, definition of, 359 
etiology of, 360-367 
pathology of, 367 
treatment of, 367, 368 
Eruption of teeth, forces producing, 62 
Essential oils, use of, in devitalizing pulps, 

424 
Ether, administration of, 215, 592-594 
as a local anaesthetic, 579, 580 
use of, in hypersensitive dentin, 215, 
216 
Ethyl chloride as a local anaesthetic, 581 
Eucaine as a local anaesthetic, 584 
Evolution of epithelial tissue, 26 
of jaws, 29 
of teeth, 30 
Examination of teeth, technique of, 112- 

114 
Excavating in hypersensitive dentin, 186, 

187 
Excavators, forms of, 226, 245 
Excision, effects of, 174 

of caries, 172, 173 
Explorers, 110 

' forms of, 111 
Extraction of dental roots, 613-617 
of teeth, 595-623 

conditions unfavorable to, 597-599 
fractures of alveolar process in, 

617, 620 
hemorrhage following, 620-623 
indications for, 595-597 
instruments used in, 600 
of impacted third molars, 618 
of inferior central and lateral in- 
cisors, 605, 606 
first and second molars, 609- 
611 
of superior and inferior bicuspids, 
607, 608 
cuspids, 606, 607 
third molars, 611-613 
central and lateral incisors, 

604, 605 
first and second molars, 508, 



Filling compound cavities with gold, 27$ 
283 
materials used in, 251 
points to be observed in, 250, 251 
simple cavities with gold, 272-278 

Fission fungi, 84 



Fistula, dento-alveolar, treatment of, 487 
Flagg on physical effects of arsenic on 

pulps, 425, 426 
Flagg' s gutta-percha softener and tool- 
heater, 334 
wafering pliers for amalgam, 324 
Floss-silk, 112, 167 
Forceps, aseptic, 602 

for extraction, 604-618 
Fractures of alveolar process in extraction. 
617, 620 
of teeth, classification of, 505 
in extraction, 619 
union after, 507, 508 



Gangrena oris, 70 

Gangrene, as result of extraction, 620 
Gates-Glidden drills, 435 
Gauze, exclusion of moisture by, 178, 179 
Gingivae (gums), histology of, 58 
Gingivitis, definition of, 541 
Gnathodynamometer, definition of, 239 
Gold, annealing of, 270, 271 
as a filling-material, 251 
cohesive, description of, 256 

foil, description and forms of, 262, 
263 
introduction of, 263 
crystal mat, in filling, 269 

preparation of, 268 
cylinders, non-cohesive, 258-260 
fillings, finishing of, 287, 288 

repairing of, 293-295 
flow of, under stress, 253, 255 
-foil (non-cohesive), method of intro- 
duction of, 258, 259 
properties of, 255-257 
use of, in filling pulp-canals, 439 
moss fibre, in filling, 269, 270 
non-cohesive, description of, 256, 257 
-pluggers, 259, 260, 264, 265, 267 
ropes and ribbons in filling, 261 
strength of, 252 
use of, in alloys, 318 
Gold-and-platinum foil, 270 
Goodsir's theory of evolution of teeth, 28 
Gouty pericementitis, 467, 550-567 
differential diagnosis of, 469 
prognosis of, 469 
symptoms and diagnosis of, 468, 

469 
treatment of, 469 
Granulation-tissue defined, 477 
Green stains upon the teeth, 521 
treatment of, 521 



(330 



Guilford's matrix, 284 
Gum-retractor, 272 
Gums (gingivae), 58 

Gutta-percha as a capping for pulps, 333, 
418 

as a filling-material, 330, 331, 441 

as a permanent filling, 333 

fillings, finishing of, 336 

in filling root-canals, 332, 441 

manipulation of, 335, 336 

physical characteristics of, 331, 332 

separating teeth with, 177 

softening, 333-335 

H 

Hematogenic calcic pericementitis, 550-567 

Haematoidin, 448, 449 

Haemosiderin, 449 

Harlan on bleaching teeth, 453 

Heated air in treatment of hypersensitive 

dentin, 189, 190 
Hemorrhage following extraction, 620-623 
treatment of, 621, 622 

from lancing gums, 73 
Herbst's burnishers for gold, 264 

method of making glass inlays, 351 
of packing non-cohesive gold, 261 
Heredity, influence of, on caries, 129 
Hewitt's method of general anaesthesia, 

589, 590 
Hill's stopping, 330 
How's cervix clamp, 181, 272 

inlay burs, 351 

thermoscopic heater for gutta-percha, 
335 
Huber on nerve-endings in pulp, 47 
Hutchinson on syphilitic teeth, 129, 130 
Hydrochloric acid, use of, in enlarging 

canals, 436 
Hydrogen dioxide as bleaching agent, 452, 

453, 456, 457 
Hyperaemia of pulp, 373, 385 
Hypercementosis, causes of, 513, 514 

pathology of, 514, 515 

symptoms and diagnosis of, 516, 517 

treatment of, 517 
Hyperplasia, definition of, 401 
Hypersensitive dentin, 162, 184 
Hypertrophy, definition of, 513 
Hypoderm, development of, 27 

I 

Immunity, definition of, 103 
Implantation, definition of, 496 
instruments used in, 498, 499 



Implantation, operation of, 498-500 

preparation of tooth for, see Trans- 
plantation 
prognosis of, 500 
requirements for, 497 
Implanted teeth, resorption of, 77 
Incisors, cavities in, compound, 229-231 
simple, 218-220, 225-227 
inferior, 8, 9 
superior, 4-8 
Incremental lines, 48 
Infectious diseases, 104 
Inflammation, definition of, 397 
forms of, 401, 402 
physical signs of, 397 
tissue changes in, 399-402 
Inflammatory phenomena, table of, 402 
Inhaler for ether administration, Allis's, 
593 
Lente's, 593 
Inlays, amalgam, 348, 349 
definition of, 346 
glass, making of, 351, 352 
gold, making of, 347 
porcelain, cavity preparation for, 354 
finishing of, 358 
manipulation of, 354-358 
methods of using, 349-351 
taking impression of cavities for, 

355, 356 
setting of, 357, 358 . 
Inostosis, definition and description of, 

515, 516 
Instruments for cohesive foil, 263-268 
for non-cohesive foil, 259 
for setting screw-posts, 248 
sterilization of, 103, 105 
used in examinations, 109-112 
Interglobular spaces, 47 
Irregularities of permanent teeth, causes 

of, 80-82 
Irritants classified, 397, 398 
Ivory's rubber-dam clamps, 181 

J 

Jack on pseudo-exposures, 417, 418 
Jack's matrices and forceps, 284 
Jaws, evolution of, 29 

growth of, 63 
Jenkins on porcelain inlays, 353 
Jodococcus vaginatus, 93, 94, 99 



Kirk on discoloration in devitalized teeth, 

446 
Kirk's method of bleaching teeth, 455 



INDEX. 



631 



Labial cavities, preparation of, 218, 219 
Lactic acid, production of, in the mouth, 

150 
Laminae, 48 

Lancing gums in primary dentition, 71, 72 
Leptothrix, 96 

buccalis maxima, 93, 97, 99 
gigantea, 95 
innominata, 92, 93, 97 
racemosa, development of, stages of, 
96-99 
Leptotrichae, definition of, 86 
Letamendi's method of local anaesthesia, 

580, 581 
Leucomaines, 103 
Libby's rubber-dam clamp, 272 
Lines of Schreger, 38 
Lingual cavities in teeth, preparation of, 

219, 220, 224, 225 
Listerine, use of, in disinfecting cavities, 

246 
Local anaesthetics, 578-586 
Local treatment of primary morbid den- 
tition, 71 
Luxation, definition of, 501 



M 

Mallet, Abbott automatic, 267 

Bonwill electro-magnetic, 266, 267 

mechanical, 267, 268 
hand, forms of, 264 
Snow and Lewis automatic, 266 
Malpighian layer, 28 
Mandrels, forms of, 293 
Matrices, forms of, 283-285 

use of, in amalgam fillings, 222, 323 
in gold fillings, 283 
McQuillen on bleaching teeth, 453 
Mechanical separation of teeth, 175, 176 
Meckel's cartilage, 30 
Medicaments used in treatment of root 

canals, 436-438 
Membrana eboris, 32, 48 
Mental strain in children predisposing to 

caries, 128, 129 
Mercurial pericementitis, 471, 473 
Mercuric chloride, use of, in phagedenic 

pericementitis, 576 
Mercury bichloride, use of, in disinfecting 

cavities, 246 
Mesio-labial cavities, preparation of, 229 
Mesio-lingual cavities, preparation of, 229 
Mesio-morsal cavities, preparation of, 231 
Mesoderm, development of, 27 



Methyl chloride as a local anaesthetic, 581 
Micrococci, classification of, 89 

description of, 88 
Micro-organisms, 84 
Miller on mummification of pulps, 444 
Miller's classification of fungi, 84 
Milliamperemeters, use of, 206 
Mirrors, forms of, 109, 110 
Miscegenation, influence of, on caries, 127, 

128 
Mitchell's electric furnace, 352 
Molars, cavities in, compound, 231-233 
simple, 220-225, 227, 228 

inferior, 21-24 
deciduous, 25 

superior, 17-21 
deciduous, 25 
Morphia acetas in hypersensitive dentin, 

187 
Morphine, use of, in devitalizing pulps, 

424 
Morsal edge cavities, preparation of, 220 
Mould fungi, description of, 84, 85 
Mouth and teeth, sterilization of, 104 

examination of, 107 

-mirrors, sterilization of, 105, 106 

-props, 592, 601 
Mucous glands, secretion of, 523 
Mummification of dental pulp, 443-445 
Mummifying pastes, formulae for, 444 

N 

Napkins, exclusion of moisture by, 178 
Nasmyth's membrane, 38 

origin and function of, 54, 55 
Nausea caused by rubber dam, treatment 

of, 183 
Necrobiosis, definition of, 518 
Necrosis as result of extraction, 620 
causes of 519, 520 
definition of, 401, 518 
of cementum, 519, 520 
treatment of, 520 
Nerve-extractors, 430-436 
Neumann, sheaths of, in caries, 159 
Nitrous oxide as a general anaesthetic, 586- 
590 
use of, in hypersensitive dentin, 
215 
Noma, 70 

O 

Obturation, definition of, 250 
Occlusal cavities, preparation of, 221-223 
Occluso-buccal cavities, preparation of, 232 
-distal cavities, preparation of, 231, 232 



632 



Occluso-lingual cavities, preparation of, 233 
-mesial cavities, preparation of, 231, 

232 
-mesio-distal cavities, preparation of, 
233 
Odontitis infantum, 70 
Odontoblasts, 32, 34, 35, 48, 422 
Operator, position of, 107 

sterilizing hands of, 104 
Ossification, 35 

Osteitis as result of extraction, 620 
Osteodentin, description of, 394 
Ottolengui on use of antiseptics in mouth, 

170 
Ottolengui' s method of preparing gutta- 
percha points, 441 
rubber-dam clamp, 181 
Oxidizing agents, forms of, 451 
Oxyhemoglobin, definition of, 447 



Palladium, use of, in alloys, 318 
Parasites classified, 84 
Parotid gland, excretion of, 523 
Parr teeth-separator, 112, 175, 176 
Pathogenic bacteria, diseases caused by, 
96 
mouth bacteria, 92 
Patient, position of, 107 
Peppermint, oil of, use of, in disinfecting 

cavities, 246 
Pepsin, use of, in extirpation of pulps, 430 
Pericemental membrane, 56 
blood-supply of, 57 
functions of, 57 
nerve-supply of, 58 
origin and composition of, 57 
Pericementitis, causes of, 459-461 
chronic, symptoms of, 466 
treatment of, 466, 467 
definition of, 450 
differential diagnosis of, 462 
general non-septic, 467 
gouty, 550-567 

hematogenic calcic, definition and 
causes of, 550-558 
pathology and morbid anat- 
omy of, 558-562 
prognosis and treatment of, 

562-567 
symptoms and diagnosis of, 

562 
varieties of, 558 
mercurial, 471, 473 
prognosis of, 473 



Pericementitis, mercurial, symptoms and 
diagnosis of, 472, 473 
treatment of, 473 
pathology of, 461 
phagedenic, causes of, 568 
definition of, 568 
differential diagnosis of, 573 
pathology of, 570 
prognosis of, 573 
symptoms and diagnosis of, 572, 

573 
treatment of, 573-577 
prognosis of, 462, 463 
ptyalogenic calcic, causes of, 541, 542 
pathology and morbid anat- 

of, 542-544 
prognosis of, 545 
symptoms and diagnosis of, 
" 544, 545 

treatment of, 545-549 
scorbutic, 470, 471 

symptoms and diagnosis of, 470, 

471 
treatment of, 471 
subacute and chronic, 465, 466 
symptoms and diagnosis of, 461, 462 
treatment of, constitutional, 464, 465 

local, 463, 464 
tubercular, 469, 470 
Pericementum, diseases of, classification 

of, 459 
Permanent teeth, calcification of, 78 
eruption of, 77 
order of, 79 
extraction of, indications for, 596, 

597 
follicles of, 33 
formula for, 2 

irregularities in eruption, causes 
of, 80 
local, 80, 82 
resorption of roots of, causes of, 
509, 510 
pathology of, 510-512 
prognosis and treatment 

of, 512 
symptoms and diagnosis 
of, 512 
Perry separator, 112, 175, 176 
Perry's hot-air syringe, 189 
Phagedenic pericementitis, 568-577 
Phagocytes, 476, 477 
Physiologic resorption, 77 
Platinum, use of, in alloys, 319 
Plug-finishing files and trimmers, 291, 292 
Porcelain inlays, 352-354, 356, 357 






633 



Potassium bromide, use of, in pericemen- 
titis, 465 
Primary epithelial cord, 30 
Prophylactic treatment of caries, 166, 170 
Proteids, analysis of, 447, 448 
Protista, definition of, 85 
Protozoa, definition of, 85 
Ptomaines, 88, 102 

Ptyalogenic calcic pericementitis, 541-549 
Pulp, calcification of tissues of, 392 
-canal pluggers, 439 
-canals, enlarging of, 435-438 
filling of, 438-443 
medicaments used in treatment of, 

436-438 
preparation and treatment of, 432- 

434 
treatment of, in pericementitis, 
463 
-capping, 418, 419 

-chamber and canals, opening of, 434, 
435 
calcic formations within, classifi- 
cation of, 390 
devitalization and extirpation of, 423, 

424, 430 
exposure of, complete, treatment of, 
423 
false, treatment of, 416, 417 
incomplete, description of, 419 
due to traumatism, 421 
prognosis of, 420, 421 
symptoms and treatment of, 
419, 420 
stages of, 416 
hypersemia of, causes and forms of, 
375-378 
definition of, 373 
from constitutional causes, 385- 

38 
from internal local causes, 384 
pathology of, 379 
prognosis of, 382, 383 
symptoms and diagnosis of, 378, 

379, 387 
treatment of, 383-385, 387, 428 
irritation of, 373, 374, 396 
mummification of, 443-445 
plethora of, definition of, 386 
suppuration of, 407^410 
forms of, 409, 410 
symptoms and diagnosis of, 410, 

411 
treatment of, 412 
Pulpitis, acute circumscribed, 403, 404 
diffuse, 404 



Pulpitis, acute, prognosis of, 405, 406 

symptoms and diagnosis of, 404, 

405 
treatment of, 406, 407 
chronic, forms of, 412 
definition of, 397 
etiology of, 402, 403 
pathology of, 403 
Pulpless teeth, 431, 432 
Pulp-stones (nodular calcifications), 391, 

392 
Pyogenic bacteria, 83, 91, 92 

action of, 102 
Pyorrhoea alveolaris, 74, 539 

bacterial origin of, 539-541 
constitutional origin of, 531-537 
definition of, 530 
etiology of, 531 
instruments used in, 547, 548 
local origin of, 537-539 
synonymes, 530 

treatment of, 545-549, 563-567, 
573-577 



Q 

Quinine, use of, in pericementitis, 465 



Recurrent hemorrhage, 621 
Replantation of teeth, 490-493 

in phagedenic pericementitis, 576 
preparation of tooth for, 491 
Replanted teeth, resorption of, 77 
Resorption of teeth, 76, 77, 509 
Retzius on nerve-endings in pulp, 46 
Rheostats, forms of, 204-206 
Richardson's method of local anaesthesia, 

579, 580 
Rigolene as a local anaesthetic, 580 
Robinson's remedy in hypersentive dentin, 

192 
Root development of teeth, 48 
Royce plugger-points, 265 
Rubber cups for polishing, 290 
dam, adjustment of, 180-182 
clamps, 172, 173, 181 
exclusion of moisture by, 177, 179, 

180 
forms of, 179 
punch, 182 
shield, 183 
sterilization of, 106 



634 



s 

Saliva, chemical reaction of, 523 
composition of, 521, 522 
description of, 133 

ejectors, exclusion of moisture by, 179 
Salivary calculi, composition of, 523, 524 
instruments used in removal of, 

528 
pathologic effects of, 526, 527 
treatment of, 527-529 
varieties of, 524-527 
Salol and paraffin, use of, in filling pulp- 
canals, 442, 443 
Schizomycetes, description of, 84 
Scorbutic pericementitis, 470, 471 
Secondary dentin, 391, 421, 422 
dentition, symptoms of, 79 
separation of teeth, methods of, 112, 
175 
Septic infection, 102 
intoxication, 102 
pulp-canals, treatment of, 431 
Sharpey's fibres, 160 
Silver, electric conductivity of, 202 
nitrate, use of, in caries, 171, 172 

in hypersensitive dentin, 192 
-tin alloys, composition of, 299, 307, 

308, 311 
use of, in alloys, 319 
Sodium dioxide as a bleaching agent, 453- 

455 
Spirilla, definition of, 86, 89 
Spirillum sputigenum, 94, 99 
Spirochete dentium, 94 
Sponge-grafting, use of, in phagedenic 

pericementitis, 577 
Staphylococcus, description of, 86 
Sterilization of instruments and hands, 
103, 104 
of mouth, antiseptics used in, 104 
technique of, 104 
Stomatitis, catarrhal, 70 

ulcerous, 70 
Stomatoscope, 111 
Stones for finishing fillings, 290 
Stratum intermedium, 39 
Streptococcus, description of, 86 
Striae of Retzius, 37 
Sublingual glands, secretions of, 523 
Submaxillary glands, secretions of, 523 
Sulphuric acid as a bleaching agent, 455 
use of, in enlarging canals, 436 
Syphilitic teeth, 129, 130 
Syringe electrode, 213 
water-, use of, 241 



Tannic acid, use of, in hemorrhage, 621 
Tape for separating teeth, 176 
Teeth, anatomy of, 3 

architectural design of, 4 
blood-supply of, 518 
calcic deposits upon, 521 
character of, in gouty subjects, 557 
deciduous, 24, 25 
development of, 26 
dislocation of, classes of, 501 
prognosis of, 504 
treatment of, 501-504 
eruption of, 59 
evolution of, 30 
examination of, 107 
extraction of, 595-623 
fractured, union of, 507, 508 
fractures of, classification of, 505 
in extraction, 619 
treatment of, 506, 507 
green stains upon, 521 
implantation of, 496-500 
morphology of, 26 
number and classification of, 1 
origin of, 26 

permanent, see Permanent teeth 
replantation of, 490-493 
transplantation of, 494-496 
Temperaments, 162, 163 
Temporary stopping, uses of, 332 
Tin and gold in combination as filling- 
material, 286, 287 
methods of introduction of, 
287 
-foil, forms of, 285 
therapeutic action of, 286 
use of, in alloys, 319 

in filling pulp-canals, 439, 440 
Tobolt's laryngeal forceps, 601 
Tomes, granular layer of, 47 

zone of, 156 
Tooth, apical foramen of, 4 
cervix of, 4 
crown of, 4 
morsal edge of, 4 
-paste, formula of, 168 
-powder, formula of, 168 
pulp-chamber of, 4 
-pulp, definition of, 55 

histological composition of, 55 
root of, 4 
Toxines, 102 
Transplantation of teeth, 494 

method of union in, 496 



635 



Transplantation of teeth, prognosis of, 496 
preparation of tooth for, see Replanta- 
tion 
Transplanted teeth, resorption of, 77 
Tropacocaine as a local anaesthetic, 583, 

584 
Truman on secondary dentin, 422 
Truman's method of bleaching teeth, 451, 

452 
Tubercular pericementitis, 469, 470 
Tubuli, bacteria in, 159 

expansion of, in caries, 157, 158 
Turnkey, use of, in extraction, 602 



Varney's gold-pluggers, 264 

Varnishes, use of, in lining cavities, 344, 
345 

Veratria in hypersensitive dentin, 187 

Von Beust's method of preparing gutta- 
percha points, 442 



W 

Warren's screw-gag, 601 
Watts' s crystal gold, 268 
Weagant's method of using porcelain in- 
lays, 350, 351 
trephines for inlays, 351 
Webb's pluggers, 264 
Wedges for separating teeth, 175, 176 
Weston's milliamperemeter, 207 
Williams on leptothrix, 99, 100 
Witzel's method of mummifying pulps, 

443 
Wood points, use of, in filling pulp-canals, 
440 
polishing-points, 289 



Woodward's double screw matrices, 285 

separator, 175 
Wright's method of bleaching teeth, 452 
Wurtz on analysis of proteids, 448 



Younger on implantation, 496 



Zinc cements in lining cavities, 327, 328 
varieties of, 336 
chloride in hypersensitive dentin, 191, 

192 
oxychloride as a capping-material, 418, 
419 
as a filling-material, 336, 337, 339 
characteristics and properties of, 

338, 339 
mixing of, 337, 338 
preparation of, 337 
use of, in filling discolored teeth, 
452, 454, 455 
in filling pulp-canals, 440, 441 
oxy phosphate as a capping-material, 
419 
crushing stress of, 343, 344 
in hypersensitive dentin, 191 
mixing and introduction of, 341, 

342 
penetration of moisture in, 343 
preparation of, 339-341 
properties and uses of, 341 
shrinkage and expansion of, 342, 
343 
oxysulphate as a capping-material, 

344, 418 
use of, in alloys, 319 



THE END. 



Oci 18 1901. 



OCT 8 BOI 










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LIBRARY OF CONGRESS 



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